1  Sys_Parameters
   Help is provided for the system parameters listed below.
 

2  ACP_BASEPRIO
   ACP_BASEPRIO sets the base priority for all ACPs. The DCL command
   SET PROCESS/PRIORITY can be used to reset the base priorities of
   individual ACPs. ACP_BASEPRIO is not applicable for XQPs.

   ACP_BASEPRIO is a DYNAMIC parameter.
 

2  ACP_DATACHECK
   ACP_DATACHECK controls the consistency checks that are performed
   on internal file system metadata such as file headers.

   ACP_DATACHECK is a bit mask. The following table shows the bits
   that are defined currently:

   Bit        Description

   0          Set this bit to perform consistency checks on read
              operations.

              When this bit is set, the IO$M_DATACHECK function
              modifier is automatically set on all subsequent IO$_
              READLBLK operations that read file system metadata (see
              the OpenVMS I/O User's Reference Manual).

   1          Set this bit to perform consistency checks on write
              operations.

              When this bit is set, the IO$M_DATACHECK function
              modifier is automatically set on all subsequent IO$_
              WRITELBLK operations that read file system metadata
              (see the OpenVMS I/O User's Reference Manual).

   2          Set this bit to perform read-after-write consistency
              checks.

              This is similar to setting bit 1, except that in this
              case the file system does the checks, not the lower
              level device or disk driver.

              Note that read-after-write consistency checks are not
              allowed on deferred writes. Deferred writes are turned
              off if this bit is set.

   3          reserved for VSI use only; must be zero.

   4          reserved for VSI use only; must be zero.

   5 and 6    These two bits control the checks that are performed on
              reads and writes of directory blocks. You can select
              one of four different levels:
                                                By
                                     Select     Setting
                                     This       Bit 6     And Bit 5
              To Check That...       Level...   to...     to...

              The block is a valid   0          0         0
              directory block
              (reads only)

              The block is a valid   1          0         1
              directory block
              (reads and writes)

              The block is a valid   2          1         0
              directory block
              and contains valid
              entries (reads and
              writes)

              The block is a valid   3          1         1
              directory block
              and contains valid
              entries in correct
              alphanumeric order
              (reads and writes)

              When you set the SYSTEM_CHECK system parameter to 1,
              you enable level 3 checking of directory blocks.

              Write errors result in BUGCHECK and crash your system;
              read errors exit with error status SS$_BADDIRECTORY.

   7          reserved for VSI use only; must be zero.
 

2  ACP_DINDXCACHE
   ACP_DINDXCACHE controls the size of the directory index cache
   and the number of buffers used on a cachewide basis. Also,
   ACP_DINDXCACHE builds a temporary index into the directory
   file, thereby reducing search time and directory header lookup
   operations.

   ACP_DINDXCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter.
 

2  ACP_DIRCACHE
   ACP_DIRCACHE sets the number of pages for caching directory
   blocks. Too small a value causes excessive XQP I/O operations,
   while too large a value causes excessive physical memory to be
   consumed by the directory data block cache.

   ACP_DIRCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter.
 

2  ACP_EXTCACHE
   ACP_EXTCACHE sets the number of entries in the extent cache.
   Each entry points to one contiguous area of free space on disk.
   A specification of 0 means no cache. Too small a value causes
   excessive XQP I/O operations, while too large a value causes
   excessive physical memory to be consumed by the extent cache.

   ACP_EXTCACHE is a DYNAMIC and FEEDBACK parameter.
 

2  ACP_EXTLIMIT
   ACP_EXTLIMIT specifies the maximum amount of free space to
   which the extent cache can point, expressed in thousandths of
   the currently available free blocks on the disk. For example,
   if available free space on the disk is 20,000 blocks, a
   specification of 10 limits the extent cache to 200 blocks.

   The computed, installed value is usually adequate. Users with
   four or more OpenVMS Cluster node systems might want to adjust
   this parameter.

   ACP_EXTLIMIT is a DYNAMIC parameter.
 

2  ACP_FIDCACHE
   ACP_FIDCACHE sets the number of file identification slots cached.
   A specification of 1 means no cache. Too small a value causes
   excessive XQP I/O operations, while too large a value causes
   excessive physical memory to be consumed by the FID caches.

   ACP_FIDCACHE is a DYNAMIC and FEEDBACK parameter.
 

2  ACP_HDRCACHE
   ACP_HDRCACHE sets the number of pages for caching file header
   blocks. Too small a value causes excessive XQP I/O operations,
   while too large a value causes excessive physical memory to be
   consumed by the file header caches.

   ACP_HDRCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter.
 

2  ACP_MAPCACHE
   ACP_MAPCACHE sets the number of pages for caching index file
   bitmap blocks. Too small a value causes excessive XQP I/O
   operations, while too large a value causes excessive physical
   memory to be consumed by the bitmap cache.

   ACP_MAPCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter.
 

2  ACP_MAXREAD
   ACP_MAXREAD sets the maximum number of directory blocks read in
   one I/O operation.

   ACP_MAXREAD is a DYNAMIC parameter.
 

2  ACP_MULTIPLE
   ACP_MULTIPLE enables (1)  or disables (0) the default creation of
   a separate disk XQP cache for each volume mounted on a different
   device type. Prior to Version 4.0, a separate ACP process was
   created for each device type if this parameter was enabled.
   Because ACP operations are now handled by the per process XQP,
   such separate processes are no longer created. In general, having
   multiple caches is unnecessary. One large cache is more efficient
   than several small ones. ACP_MULTIPLE can be overridden on an
   individual-volume basis with the DCL command MOUNT.

   ACP_MULTIPLE is an AUTOGEN and DYNAMIC parameter.
 

2  ACP_QUOCACHE
   ACP_QUOCACHE sets the number of quota file entries cached. A
   specification of 0 means no cache. Too small a value causes
   excessive XQP I/O operations, while too large a value causes
   excessive physical memory to be consumed by the quota caches.

   ACP_QUOCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter.
 

2  ACP_REBLDSYSD
   ACP_REBLDSYSD specifies whether the system disk should be rebuilt
   if it was improperly dismounted with extent caching, file number
   caching, or disk quota caching enabled. The ACP_REBLDSYSD default
   value (1)  ensures that the system disk is rebuilt. Setting the
   value to 0 means the disk is not rebuilt.

   Depending on the amount of caching enabled on the volume
   before it was dismounted, the rebuild operation may consume a
   considerable amount of time. Setting the value of ACP_REBLDSYSD
   to 0 specifies that the disk should be returned to active service
   immediately. If you set ACP_REBLDSYSD to 0, you can enter the DCL
   command SET VOLUME/REBUILD at any time to rebuild the disk.
 

2  ACP_SHARE
   ACP_SHARE enables (0)  or disables (1) the creation of a global
   section for the first ACP used, enabling succeeding ACPs to share
   its code. This parameter should be set to 0 when ACP_MULTIPLE is
   on.

   ACP_SHARE is a DYNAMIC parameter.
 

2  ACP_SWAPFLGS
   ACP_SWAPFLGS enables or disables swap through the value of a
   4-bit number for the following four classes of ACPs:

   Bit    Class of ACP

   0      Disks mounted by MOUNT/SYSTEM

   1      Disks mounted by MOUNT/GROUP

   2      Private disks

   3      Magnetic tape ACP

   If the value of the bit is 1, the corresponding class of ACPs
   can be swapped. The value of decimal 15 (hexadecimal F-all bits
   on) enables swap for all classes of ACP. A value of decimal
   14 disables swap for ACPs for volumes mounted with the /SYSTEM
   qualifier but leaves swap enabled for all other ACPs. Note that
   one has only disk ACPs present if they are specifically requested
   at mount time or if a Files-11 On-Disk Structure Level 1 disk is
   mounted. In general, only bit 3 is significant because usually no
   file ACPs exist.

   ACP_SWAPFLGS is an AUTOGEN and DYNAMIC parameter.
 

2  ACP_SYSACC
   ACP_SYSACC sets the number of directory file control blocks
   (FCBs) that are cached for disks mounted with the /SYSTEM
   qualifier. Each directory FCB contains a 16-byte array containing
   the first letter of the last entry in each block of the directory
   (or group of blocks if the directory exceeds 16 blocks). Since
   entries in a directory are alphabetical, the cached FCB provides
   quick access to a required directory block. This parameter value
   should be roughly equivalent to the number of directories that
   are in use concurrently on each system volume. It might be
   overridden on a per-volume basis with the /ACCESSED qualifier
   to the DCL command MOUNT. The value should be kept low in systems
   with small physical memory and little file activity, because
   the FCBs require a significant amount of space in the nonpaged
   dynamic pool.

   Too small a value causes excessive XQP I/O operations, while too
   large a value causes excessive physical memory to be consumed by
   the FCB caches.

   ACP_SYSACC is an AUTOGEN and DYNAMIC parameter.
 

2  ACP_WINDOW
   ACP_WINDOW sets the default number of window pointers to be
   allocated in a window for a default file access, for disks
   mounted with the /SYSTEM qualifier.

   ACP_WINDOW is a DYNAMIC parameter.
 

2  ACP_WORKSET
   ACP_WORKSET sets the default size of a working set for an ACP.
   A specification of 0 permits the ACP to calculate the size. This
   value should be nonzero only on small systems where memory is
   tight. Too small a value causes excessive ACP page, while too
   large a value causes excessive physical memory to be consumed
   by the ACP. Note that this parameter has no effect on the per-
   process XQP.

   ACP_WORKSET is a DYNAMIC parameter.
 

2  ACP_WRITEBACK
   ACP_WRITEBACK is a dynamic system parameter that controls whether
   deferred writes to file headers are enabled. The default value is
   1, which enables deferred writes to file headers. To disable the
   feature, set ACP_WRITEBACK to 0.

   This system parameter affects only applications like PATHWORKS
   that can request deferred writes to file headers. Note that
   the deferred write feature is not available on Files-11 ODS-1
   volumes.

   ACP_WRITEBACK is a DYNAMIC parameter.
 

2  ACP_XQP_RES
   ACP_XQP_RES controls whether the XQP is currently in memory.
   The default value (1) specifies that the XQP is permanently in
   memory. Change the default only on restricted memory systems
   with a small number of users and little or no file activity that
   requires XQP intervention. Such activity includes file opens,
   closes, directory lookups, and window turns.
 

2  AFFINITY_SKIP
   AFFINITY_SKIP controls the breaking of implicit affinity. The
   value indicates the number of times a process is skipped before
   being moved.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  AFFINITY_TIME
   AFFINITY_TIME controls the breaking of implicit affinity. The
   value indicates how long a process remains on the compute queue.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  ALLOCLASS
   ALLOCLASS determines the device allocation class for the system.
   The device allocation class is used to derive a common lock
   resource name for multiple access paths to the same device.
 

2  ARB_SUPPORT
   (Alpha and Integrity servers) The Access Rights Block (ARB)
   compatibility option, the ARB_SUPPORT system parameter, is
   provided specifically to support products that have not yet been
   updated to use the new per-thread security Persona Security Block
   (PSB) data structure instead of the ARB. Changing the value of
   ARB_SUPPORT from 2 or 3 (the default) to any other value can
   affect the operation of these products.

                                  NOTE

      VSI recommends that all Version 7.3-1 systems have the
      ARB_SUPPORT parameter set to 3 (the default). Do not change
      the ARB_SUPPORT parameter to any other value until all
      products dependent on the ARB and associated structures
      have been modified for the new environment.

   The following table describes ARB_SUPPORT parameters:

   ARB_SUPPORT
   Parameter         Value    Behavior

   ISS$C_ARB_NONE    0        The obsolete kernel data cells are not
                              maintained by the system. Fields are
                              initialized to zero (or set to invalid
                              pointers) at process creation.

   ISS$C_ARB_CLEAR   1        The obsolete kernel data cells are
                              cleared (or set to invalid pointers)
                              when the code would have set up values
                              for backward compatibility.

   ISS$C_ARB_READ_   2        The obsolete cells are updated with
   ONLY                       corresponding security information
                              stored in the current PSB when a
                              $PERSONA_ASSUME is issued.

   ISS$C_ARB_FULL    3 (de-   Data is moved from the obsolete cells
                     fault)   to the currently active PSB on any
                              security-based operation.

   ARB_SUPPORT is a DYNAMIC parameter.
 

2  AUTO_DLIGHT_SAV
   AUTO_DLIGHT_SAV is set to either 1 or 0. The default is 0.

   If AUTO_DLIGHT_SAV is set to 1, OpenVMS automatically makes the
   change to and from daylight saving time.
 

2  AWSMIN
   On Alpha and Integrity servers, AWSMIN establishes the lowest
   number of pagelets to which a working set limit can be decreased
   by automatic adjustment of the working set.

   AWSMIN is a DYNAMIC parameter.
 

2  AWSTIME
   AWSTIME specifies the minimum amount of processor time that
   must elapse for the system to collect a significant sample of
   a working set's page fault rate. The time is expressed in units
   of 10 milliseconds. The default value of 5, for example, is 50
   milliseconds.

   Some application configurations that have a large number of
   memory-intensive processes may benefit if the value is reduced.
   The value can be as low as 4.

   AWSTIME expiration is checked only at quantum end. Reducing its
   value and not reducing QUANTUM effectively sets the value of
   AWSTIME equal to the value of QUANTUM.

   AWSTIME is a DYNAMIC parameter.
 

2  BALSETCNT
   BALSETCNT sets the number of balance set slots in the system page
   table. Each memory-resident working set requires one balance set
   slot.

   You can monitor the active system with the DCL command SHOW
   MEMORY or the MONITOR PROCESSES command of the Monitor utility to
   determine the actual maximum number of working sets in memory. If
   this number is significantly lower than the value of BALSETCNT,
   this parameter value could be lowered. If all balance set slots
   are being used, raise the value of BALSETCNT.

   Never set BALSETCNT to a value higher than 2 less than
   MAXPROCESSCNT. If physical memory is a significant system
   constraint, consider lowering this value even further. However,
   if your system runs with a number of processes nearly equal to
   MAXPROCESSCNT, lowering BALSETCNT forces swapping to occur, which
   can affect system performance.

   BALSETCNT is no longer a strict setting of the number of
   processes that might be resident in memory. The swapper tries
   to reduce the number of resident processes down to BALSETCNT.
   However, if the total number of active processes and processes
   that have disabled swapping exceeds BALSETCNT, the swapper does
   not force processes out of memory just to meet the BALSETCNT
   setting.

   BALSETCNT is an AUTOGEN, GEN, DYNAMIC, and MAJOR parameter.
 

2  BORROWLIM
   BORROWLIM defines the minimum number of pages required on the
   free-page list before the system permits process growth beyond
   the working set quota (WSQUOTA) for the process. This parameter
   should always be greater than FREELIM.

   This parameter allows a process to grow beyond the value set by
   the working set quota (WSQUOTA) to the working set quota extent
   (WSEXTENT) on a system that has a substantial memory on the free-
   page list. This automatic working set adjustment also depends
   upon the values of parameters WSINC, PFRATH, and AWSTIME.

   Working set growth attempts to alleviate heavy page faulting. To
   make use of this growth, you must also set the user's WSEXTENT
   authorization quota to a larger number than the WSQUOTA value.

   BORROWLIM is an AUTOGEN, DYNAMIC and MAJOR parameter.
 

2  BREAKPOINTS
   If XDELTA is loaded, BREAKPOINTS enables additional built-in
   calls for XDELTA during the boot sequence. The breakpoints that
   are enabled may change from release to release of OpenVMS.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   BREAKPOINTS is a DYNAMIC parameter.
 

2  BUGCHECKFATAL
   BUGCHECKFATAL enables or disables the conversion of nonfatal
   bugchecks into fatal bugchecks. The system must be rebooted on a
   fatal bugcheck. A nonfatal bugcheck places an entry only in the
   error log and deletes the corresponding process.

   This parameter should normally be OFF (0);  you should set it ON
   (1)  only when the executive is being debugged.

   Setting the SYSTEM_CHECK parameter to 1 has the effect of setting
   BUGCHECKFATAL to ON (1).

   BUGCHECKFATAL is a DYNAMIC parameter.
 

2  BUGREBOOT
   BUGREBOOT enables or disables automatic rebooting of the system
   if a fatal bugcheck occurs. This parameter should normally be on
   (1);  set it off (0) only when the executive is being debugged.

   BUGREBOOT is a DYNAMIC parameter.
 

2  CHANNELCNT
   CHANNELCNT specifies the maximum number of I/O channels available
   to processes and to the system. The FILLM quota can be used
   to reduce the maximum number of I/O channels for a process. A
   process with a FILLM quota larger than CHANNELCNT is nevertheless
   limited to the maximum number of I/O channels specified by
   CHANNELCNT.
 

2  CLASS_PROT
   CLASS_PROT performs the nondiscretionary classification
   checks. CLASS_PROT is also checked by XQP to determine if a
   classification block should be added to the header of any created
   files.

   CLASS_PROT is a DYNAMIC parameter.
 

2  CLISYMTBL
   CLISYMTBL sets the size of the command interpreter symbol table,
   which controls the number of DCL symbols that can be created.

   CLISYMTBL is a DYNAMIC parameter.
 

2  CLUSTER_CREDITS
   CLUSTER_CREDITS specifies the number of per-connection buffers a
   node allocates to receiving VMS$VAXcluster communications.

   If the SHOW CLUSTER command displays a high number of credit
   waits for the VMS$VAXcluster connection, you might consider
   increasing the value of CLUSTER_CREDITS on the other node.
   However, in large cluster configurations, setting this value
   unnecessarily high consumes a large quantity of nonpaged pool.
   Each receive buffer is at least SCSMAXMSG bytes in size but might
   be substantially larger depending on the underlying transport.

   It is not required for all nodes in the cluster to have the same
   value for CLUSTER_CREDITS.

   The default value is currently 32. Unless a system has very
   constrained memory available, VSI recommends that these values
   not be increased.
 

2  CONCEAL_DEVICES
   CONCEAL_DEVICES enables or disables the use of concealed devices.
   By default, this parameter is set to enable concealed devices
   (1).

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  CPU_POWER_MGMT_(D)
   On Integrity servers, a CPU can be placed in "low-power mode"
   when it is idle. This minimizes power consumption, thereby
   reducing energy costs for the system. Beginning in Version 8.2-
   1, OpenVMS Integrity servers supports this feature based on the
   settings of two system parameters: CPU_POWER_MGMT and CPU_POWER_
   THRSH.

   A value of 1 for CPU_POWER_MGMT means on (the default); a value
   of 0 means off. Whenever the CPU_POWER_THRSH parameter value is
   exceeded, the operating system places an Integrity processor in
   low-power mode if it is idle. OpenVMS Integrity servers does this
   only if CPU_POWER_MGMT is on. A CPU returns to normal power when
   it receives an interrupt.

   CPU_POWER_MGMT is a DYNAMIC parameter.
 

2  CPU_POWER_THRSH_(D)
   On Integrity servers, CPU_POWER_THRSH is a parameter expressed
   as a percentage. OpenVMS Integrity servers monitors how active
   each CPU is over a fixed time period. If CPU_POWER_MGMT is on
   and a CPU is idle for a period of time indicated by CPU_POWER_
   THRSH, the CPU is placed in a low-power mode if it is idle. A CPU
   returns to normal power when it receives an interrupt.

   For systems supporting real-time operations that require quick
   response time, VSI recommends that this feature be turned off. Use
   of this feature can result in a small performance degradation.

   For more information, see the Intel IA-64 Architecture Software
   Developer's Manual, Volume 2: IA-64 System Architecture.

   See also the CPU_POWER_MGMT parameter.

   CPU_POWER_THRSH is a DYNAMIC parameter.
 

2  CRD_CONTROL
   This special parameter is use by VSI and is subject to change.
   Do not change this parameter unless VSI recommends that you do so.
   On Alpha and Integrity servers, CRD_CONTROL can be used to expand
   the function defined by CRDENABLE.

   CRD_CONTROL is a bit mask for corrected read data (CRD) soft
   error control flags. These flags control the use of CRDERROR
   routines.

   On Alpha and Integrity servers, the following bits are defined:

   Bit    Description

   0      Enables CRD processing for all systems.

   1      Enables scrubbing (rewriting) of the memory location that
          induced the CRD.

   2      Enables page replacement of the pages that exhibit
          repeated CRD errors.

   3      Forces all memory pages to be included in the PFN
          database. On systems that contain more than 512 megabytes
          of memory, all memory is mapped by the PFN database by
          default. This bit allows the mapping to occur on systems
          with less than 512 megabytes of memory.

   4      Enables extended CRD handling, if available.

   5      Enables loading of driver and process for handling server
          management events. Platform-specific code usually sets
          this bit if the required hardware and firmware support are
          available.

   6      Disables CRD throttling.

   7      Disables System Event Log (SEL) polling.

   16-31  Reserved for platform-specific error-handling control.

   On Alpha and Integrity servers, the default setting is 22, which
   enables scrubbing, page replacement, and extended CRD handling.
 

2  CRDENABLE
   (Alpha and Integrity servers) CRDENABLE enables or disables
   detection and logging of memory-corrected read data (ECC) errors.
   This parameter should normally be set to (1).

   Beginning with OpenVMS Version 7.2, CRD_CONTROL can expand the
   function of CRDENABLE. (See CRD_CONTROL.)
 

2  CTLIMGLIM
   CTLIMGLIM specifies the size of the default image I/O segment;
   that is channel table and initial buffer pool for image-related
   file and RMS I/O.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  CTLPAGES
   CTLPAGES specifies the size of P1 pool. CTLPAGES is automatically
   changed only when the process logical name table, DCL symbols, or
   some layered products require an increase in the size of the P1
   pool area.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   CTLPAGES is an AUTOGEN parameter.
 

2  CWCREPRC_ENABLE
   CWCREPRC_ENABLE controls whether an unprivileged user can create
   a process on another OpenVMS Cluster node. The default value of 1
   allows an unprivileged user to create a detached process with the
   same UIC on another node. A value of 0 requires that a user have
   DETACH or CMKRNL privilege to create a process on another node.
 

2  DBGTK_SCRATCH
   (Alpha and Integrity servers) DBGTK_SCRATCH specifies how many
   pages of memory are allocated for the remote debugger. This
   memory is allocated only if remote debugging is enabled with the
   8000 boot flag. Normally, the default value is adequate, but if
   the remote debugger issues an error message, you should increase
   this value. See Writing OpenVMS Alpha Device Drivers in C (Margie
   Sherlock and Lenny S. Szubowicz, Digital Press, 1996). for more
   information. (This manual has been archived.)
 

2  DCL_CTLFLAGS
   DCL_CTLFLAGS is a bit mask that alters default behavior for
   certain DCL-related functions on a systemwide basis. However,
   the default values satisfy the needs of most systems.

   Bits 0 and 2 control the formulation of system-generated process
   names for processes created using the SPAWN command or LIB$SPAWN
   library routine. They are provided for compatibility with
   behavior of prior OpenVMS versions. Note that you can eliminate
   the use of system-generated names by supplying your own process
   names.

   Bit 1 controls the token size used by DCL.

   Bit 3 controls the maximum number input parameters to command
   procedure.

   Bit 4 controls the the maximum length for an user name, for which
   OpenVMS mail forwarding address is set.

   DCL_CTLFLAGS bits are described in the following table.

   Bit   Description

   Bit   If clear (the default), the numeric portion of a system-
   0     generated spawned process name is generated randomly. If
         set, the numeric portion is generated sequentially starting
         with sequence number 1.

         The option of sequential generation is provided for
         compatibility with OpenVMS versions prior to Version
         7.3-1. However, this choice can be very expensive in
         performance terms because of the mechanism for finding
         the next available process name. This mechanism attempts to
         create all process names beginning with sequence number 1
         until it finds one that is unused.

         Random generation is the preferred choice because it
         results in a very high probability of finding a unique
         name on the first try.

   Bit   Controls the token size used by DCL. If clear (the
   1     default), this bit instructs DCL to use the traditional
         token size. A token cannot exceed 255 characters. If this
         bit is set, extended tokens are used. Extended tokens are
         4000 characters.

         Note that if you turn on extended tokens, file
         specifications can exceed 255 characters, which might
         require larger structures for parsing file specifications.


   Bit   If clear (the default), the numeric portion of a system-
   2     generated spawned process name has a maximum value of
         65535. If set, the numeric portion of the name has a
         maximum value of 255.

         The option of a maximum of 255 is provided for
         compatibility with OpenVMS versions prior to Version 8.3,
         when it was the only choice. The larger maximum allows many
         more unique spawned process names for a given process.
         For this reason, it is the preferred choice. However,
         the larger maximum uses two additional characters from
         the process name, which might make it more difficult to
         identify users uniquely by looking at their spawned process
         names. If this is an issue on your system, setting bit 2
         might be a better choice.


   Bit   If clear (the default), command procedure supports the
   3     default eight optional parameters (that is, (P1,P2,...P8)).
         If set, command procedure supports up to sixteen optional
         parameters (that is, (P1,P2,...P16)). This is also
         applicable when using the CALL command to transfer control
         to a subroutine.


   Bit   This bit controls the the maximum length for an user name,
   4     for which OpenVMS mail forwarding address is set. If clear
         (the default), user name string length is set to a maximum
         length of 31 characters. If set, user name string length is
         set to a maximum of 255 characters.

         Note: Once this bit is set, user name length is set to
         maximum of 255 characters. Even if this bit is cleared,
         the behavior remains unchanged, that is, supports user name
         length of 255 characters, but there is no way to reset it
         to 31 characters.
 

2  DEADLOCK_WAIT
   DEADLOCK_WAIT defines the number of seconds that a lock request
   must wait before the system initiates a deadlock search on behalf
   of that lock. Setting DEADLOCK_WAIT to zero disables deadlock
   checking. Setting DEADLOCK_WAIT to a value greater than zero
   and less than the default setting provides faster detection of
   deadlocks but requires more CPU usage.

   The DEADLOCK_WAIT value is expressed in seconds; therefore, the
   smallest value you can set is 1 second. Beginning in VSI OpenVMS
   Version 8.3, a subsecond deadlock wait time, which is set in
   the system service $SET_PROCESS_PROPERTIESW item code $PPROP$C_
   DEADLOCK_WAIT, overrides DEADLOCK_WAIT. For more information, see
   the $SET_PROCESS_PROPERTIESW system service in VSI OpenVMS System
   Services Reference Manual.

   DEADLOCK_WAIT is a DYNAMIC parameter.
 

2  DEFGID
   Default POSIX GID used internally by OpenVMS.
 

2  DEFMBXBUFQUO
   DEFMBXBUFQUO sets the default for the mailbox buffer quota size
   in bytes when this value is not specified in a Create Mailbox
   ($CREMBX) system service call.

   DEFMBXBUFQUO is a DYNAMIC parameter.
 

2  DEFMBXMXMSG
   DEFMBXMXMSG sets the default for the mailbox maximum message size
   in bytes when this value is not specified in a Create Mailbox
   ($CREMBX) system service call.

   DEFMBXMXMSG is a DYNAMIC parameter.
 

2  DEFPRI
   DEFPRI sets the base default priority for processes.

   DEFPRI is a DYNAMIC parameter.
 

2  DEFQUEPRI
   DEFQUEPRI establishes the scheduling priority for jobs entered
   in batch and output (printer, server, and terminal) queues when
   no explicit scheduling priority is specified by the submitter.
   The value of this parameter can range from 0 to 255; the default
   value is 100.

   The value of DEFQUEPRI should be less than or equal to MAXQUEPRI.

                                  NOTE

      DEFQUEPRI refers to relative queue scheduling priority, not
      the execution priority of the job.

   DEFQUEPRI is a DYNAMIC parameter.
 

2  DEFUID
   Default POSIX UID used internally by OpenVMS.
 

2  DELPRC_EXIT
   DELPRC_EXIT can be used to control $DELPRC system service options
   that call exit handlers prior to final cleanup and deletion of a
   process. The following table describes these options:

   Option         Description

   0              Disable the exit handler functionality with
                  $DELPRC.

   4              Execute kernel mode exit handlers.

   5 (default)    Execute exec and more privileged mode exit
                  handlers.

   6              Execute supervisor and more privileged mode exit
                  handlers.

   7              Execute user and more privileged mode exit
                  handlers.

   DELPRC_EXIT is a DYNAMIC parameter.
 

2  DEVICE_NAMING
   (Alpha and Integrity servers) DEVICE_NAMING is a bit mask
   indicating whether port allocation classes are used in forming
   SCSI device names.

   Following is the bit definition:

   Bit   Definition

   0     If 1, enable new naming.

   1     Must be 0. This bit is Reserved for use by VSI.

   2     If 1, cloned device unit numbers wrap after 9999(not 65472).
  
   3     If 1, cloned device unit numbers wrap after 32767(not 65472).

         Note that even if both bits are zero, device unit numbers will
         wrap after 9999 if "nodename$" is prefixed to the name of the
         device in question (e.g. VMS123$DKA100:); devices whose drivers
         support larger device numbers will wrap after 65472 (or 32767
         if bit 3 is set) only if the nodename is not built into the
         device name.
   
   For more information about port allocation classes, see the VSI
   OpenVMS Cluster Systems manual.
 

2  DISABLE_UPCALLS
   DISABLE_UPCALLS is primarily a debugging aid. It allows the
   system manager to disable threads upcalls of specific types
   for the entire system. The value is a bit mask, with the bits
   corresponding to the upcall types. The upcall types are defined
   in the definition macro $TMCDEF.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   DISABLE_UPCALLS is a DYNAMIC parameter.
 

2  DISK_QUORUM
   The DISK_QUORUM parameter is the name of an optional quorum disk
   in ASCII. ASCII spaces indicate that no quorum disk is being
   used.
 

2  DISMOUMSG
   DISMOUMSG controls whether the messages that log volume dismounts
   appear on the operator's terminal and in the operator's log. The
   default value of 0 disables reporting of these messages.

   DISMOUMSG is a DYNAMIC parameter.
 

2  DNVOSI1
   DNVOSI1 is reserved to DECnet-Plus for OpenVMS. This special
   parameter is use by VSI and is subject to change. Do not change
   this parameter unless VSI recommends that you do so.
 

2  DORMANTWAIT
   DORMANTWAIT specifies, in seconds, the amount of time that can
   elapse without a significant event before the system treats
   a low-priority computable process as a DORMANT process for
   scheduling purposes. (A low-priority process is a non real-time
   process whose current priority is equal to or less than the value
   specified by the system parameter DEFPRI [default=4].) After
   SUSP (suspended) processes, DORMANT processes are the most likely
   candidates for memory reclamation by the swapper.

   Increasing the value of DORMANTWAIT can increase the interval
   that a low priority process blocks a high priority process if
   that low priority process is holding a lock or resource that the
   higher priority process is waiting for.

   DORMANTWAIT is a DYNAMIC parameter.
 

2  DR_UNIT_BASE
   (Alpha only) DR_UNIT_BASE specifies the base value from which
   unit numbers for DR devices (DIGITAL StorageWorks RAID Array 200
   Family logical RAID drives) are counted.

   DR_UNIT_BASE provides a way for unique RAID device numbers to
   be generated. DR devices are numbered starting with the value of
   DR_UNIT_BASE and then counting from there. For example, setting
   DR_UNIT_BASE to 10 produces device names such as $1$DRA10,
   $1$DRA11, and so on.

   Setting DR_UNIT_BASE to appropriate, nonoverlapping values on all
   cluster members that share the same (nonzero) allocation class
   ensures that no two RAID devices are given the same name.

   DR_UNIT_BASE is a GEN parameter.
 

2  DUMPBUG
   DUMPBUG enables (1)  or disables (0) the writing of error log
   buffers and memory contents to SYS$SYSTEM:SYSDUMP.DMP when a
   fatal bugcheck occurs. This parameter should be off (0)  only
   when the executive is being debugged.
 

2  DUMPSTYLE
   DUMPSTYLE specifies the method of writing system dumps.

   DUMPSTYLE is a 32-bit mask, with the following bits defined.
   Each bit can be set independently. The value of the system
   parameter is the sum of the values of the bits that have been
   set. Remaining or undefined values are reserved for VSI use only.

   Bit              Mask       Description

   0                00000001   0 =  Full dump (SYSGEN default).
                                    The entire contents of physical
                                    memory are written to the dump
                                    file.
                               1 =  Selective dump. The contents of
                                    memory are written to the dump
                                    file selectively to maximize
                                    the usefulness of the dump file
                                    while conserving disk space.

   1                00000002   0 =  Minimal console output.
                               1 =  Full console output (includes
                                    stack dump, register contents,
                                    and so on).
   2                00000004   0 =  Dump to system disk.

                               1 =  Dump off system disk (DOSD) to
                                    an alternate disk. (see the VSI
                                    OpenVMS System Manager's Manual
                                    for details.)

   3 (Alpha and     00000008   0 =  Do not compress.
   Integrity
   servers)
                               1 =  Compress. (VAX systems do not
                                    support dump compression.)

   4 (Alpha and     00000010   0 =  Dump shared memory.
   Integrity
   servers)
                               1 =  Do not dump shared memory. (VAX
                                    systems do not support shared
                                    memory.)

   5 - 14                           reserved for VSI use only.

   15 (VAX only)    00008000   0 =  Disable use of bits 16 - 27.
                                    (Specific to VAX 7000s.)
                               1 =  Enable use of bits 16 - 27.

   16 - 27 (VAX     0FFF0000        Range of DOSD unit numbers. (VAX
   only)                            systems do not support shared
                                    memory.)

   28 - 31                          reserved for VSI use only.

   If you plan to enable the Volume Shadowing minimerge feature on
   an Alpha or Integrity servers disk, be sure to specify DOSD to an
   alternate disk.

                                  NOTE

      On Alpha and Integrity servers, you can save space on
      the system disk and, in the event of a crash, save time
      recording the system memory, by using the OpenVMS Alpha
      and Integrity servers dump compression feature. Unless
      you override the default AUTOGEN calculations (by setting
      DUMPSTYLE in MODPARAMS.DAT), AUTOGEN uses the following
      algorithm:

      o  On a system with less than 128 MB of memory, the system
         sets the DUMPSTYLE to 1 (a raw selective dump) and sizes
         the dump file appropriately.

      o  On a system with 128 MB of memory or greater, the system
         sets the DUMPSTYLE to 9 (a compressed selective dump),
         and creates the dump file at two-thirds the value of the
         corresponding raw dump.

   Examples:

   The mask of 00000006 directs the system to send a full dump, with
   full console output, off the system disk (to the alternate disk).

   For a VAX 7000, a mask of 00098006 directs the system to send a
   full dump with full console output to the DOSD whose unit number
   is 9.

   On Alpha and Integrity servers, the mask of 00000009 directs the
   system to compress a selective dump with minimal console output.

   DUMPSTYLE has AUTOGEN and DYNAMIC attributes.
 

2  ERLBUFFERPAG_S2
   ERLBUFFERPAG_S2 specifies the amount of S2 space memory to
   allocate for each S2 space error log buffer requested by the
   ERRORLOGBUFF_S2 parameter.

   If you increase ERLBUFFERPAG_S2, you must either run AUTOGEN or
   manually increase the size of both the system dump file and the
   error log dump file.

   ERLBUFFERPAG_S2 is an AUTOGEN parameter on Alpha and Integrity
   servers.
 

2  ERLBUFFERPAGES
   ERLBUFFERPAGES specifies the amount of S0 space memory to
   allocate for each S0 space error log buffer requested by the
   ERRORLOGBUFFERS parameter.

   ERLBUFFERPAGES is an AUTOGEN parameter on Alpha and Integrity
   servers.
 

2  ERRORLOGBUFF_S2
   ERRORLOGBUFF_S2 specifies the number of S2 space error log
   buffers reserved for system error log entries. Each buffer
   is ERLBUFFERPAG_S2 in length. If ERRORLOGBUFF_S2 is too low,
   messages might not be written to the error log file. If it is too
   high, the buffers can consume unnecessary physical pages.

   If you increase ERRORLOGBUFF_S2, you must either run AUTOGEN or
   manually increase the size of both the system dump file and the
   error log dump file.

   ERRORLOGBUFF_S2 is an AUTOGEN parameter on Alpha and Integrity
   servers.
 

2  ERRORLOGBUFFERS
   ERRORLOGBUFFERS specifies the number of S0 space error log
   buffers reserved for system error log entries. Each buffer is
   ERLBUFFERPAGES in length. If ERRORLOGBUFFERS is too low, messages
   might not be written to the error log file. If it is too high,
   the buffers can consume unnecessary physical pages.

   ERRORLOGBUFFERS is an AUTOGEN parameter on Alpha and Integrity
   servers.
 

2  EXECSTACKPAGES
   (Alpha and Integrity servers) EXECSTACKPAGES controls the number
   of pages allocated for each RMS exec stack.

   EXECSTACKPAGES is a DYNAMIC parameter.
 

2  EXPECTED_VOTES
   EXPECTED_VOTES specifies the maximum number of votes that can be
   present in a cluster at any given time. Set it to a value that is
   equal to the sum of the vote parameters of all cluster members,
   plus any votes that are contributed by the quorum disk. This
   value is used to automatically derive the number of votes that
   must be present for the cluster to function (quorum).

   EXPECTED_VOTES is an AUTOGEN attribute parameter.
 

2  EXTRACPU
   EXTRACPU sets the time, in units of 10 ms, allotted to each of a
   process's exit handlers (for each access mode) after the process
   times out (that is, reaches its CPU time limit).

   EXTRACPU is a DYNAMIC attribute parameter.
 

2  FAST_PATH
   (Alpha and Integrity servers) FAST_PATH is a static system
   parameter that enables (1) or disables (0) the Fast Path
   performance features for all Fast Path-capable ports.

   Starting in OpenVMS Version 7.2, FAST_PATH is enabled by default.
   In Versions 7.0 and 7.1, FAST_PATH was disabled by default.

   For additional information, see FAST_PATH_PORTS.
 

2  FAST_PATH_PORTS
   (Alpha and Integrity servers) FAST_PATH_PORTS is a static
   parameter that deactivates Fast Path for specific drivers.

   FAST_PATH_PORTS is a 32-bit mask, with a bit assigned for each
   Fast Path port driver. The following table describes the bit
   values:

   Bit
   Value    Description

   1        Indicates that Fast Path is disabled for ports serviced
            by the corresponding driver.

   0        Indicates that Fast Path is not disabled for ports
            serviced by the corresponding driver.

   Beginning in OpenVMS Version 7.3-1, values of specific bit
   positions are those described in the following table:

   Bit
   Position Description

   0        Controls Fast Path for PKQDRIVER (for parallel SCSI).

   1        Controls Fast Path for FGEDRIVER (for Emulex LP7000,
            LP8000, LP9002, LP9802, LP10000 FibreChannel).

   2        Controls Fast Path for PKADRIVER (for Adaptec AIC-78xx
            Ultra3 SCSI).

   3        Controls Fast Path for PEDRIVER (for LAN).

   4        Controls Fast Path for PKRDRIVER (for SMART Array 5300).

   5        Controls Fast Path for PKMDRIVER, the LSI Logic
            LSI53C1030 SCSI port driver.

   6        Controls Fast Path for PGQDRIVER, the Qlogic ISP23xx
            FibreChannel port driver.

   Currently, the default setting for FAST_PATH_PORTS is 0, which
   means that Fast Path is enabled for all drivers that appear in
   the table.

   In addition, note the following:

   o  CI drivers are not controlled by FAST_PATH_PORTS. Fast Path
      for CI is enabled and disabled exclusively by the FAST_PATH
      system parameter.

   o  FAST_PATH_PORTS is relevant only if the FAST_PATH system
      parameter is enabled (equal to 1). Setting FAST_PATH to zero
      has the same effect as setting all the bits in FAST_PATH_PORTS
      to 1.

   For additional information, see FAST_PATH. For an explanation of
   how to set the bits, see the OpenVMS I/O User's Reference Manual.
 

2  FREEGOAL
   FREEGOAL establishes the number of pages that you want to
   reestablish on the free-page list following a system memory
   shortage. Memory shortages occur when the system drops below the
   minimum number of pages required on the free-page list (FREELIM).
   The value of FREEGOAL must always be greater than or equal to the
   value of FREELIM.

   FREEGOAL has the AUTOGEN, DYNAMIC, and MAJOR attributes.
 

2  FREELIM
   FREELIM sets the minimum number of pages that must be on the
   free-page list.

   The system writes pages from the modified-page list, swaps out
   working sets, or reduces the size of the working sets to maintain
   the minimum count.

   While the larger free-page list generally means less page I/O, it
   also means less space for the balance set, which tends to result
   in more swap I/O. You can monitor the size of the free-page list,
   the amount of page, and the amount of swap with the MONITOR IO
   command of the Monitor utility.

   FREELIM has the AUTOGEN and MAJOR attributes.
 

2  GALAXY
   (Alpha Galaxy platforms only) The GALAXY parameter sets memory
   sharing.

   Specify one of the following:

   Value    Description

   0        The default. Do not participate in a memory sharing.

   1        Participate in a memory sharing.

   When you set GALAXY to 1 in a hard partition, OpenVMS instances
   will share memory between soft partitions within that hard
   partition. (You can run more than two soft partitions in a hard
   partition, and you might might not want to share memory among all
   of them.) Note that GALAXY specifies only if a node uses shared
   memory. You do not need to use the parameter to run multiple
   cooperative instances of OpenVMS; you do this by console setup of
   the configuration tree that you want.
 

2  GBLPAGES
   GBLPAGES sets the number of global page table entries allocated
   at bootstrap time. Each global section requires 1 global page
   table entry per section page, plus 2 entries, with the total
   rounded up to an even number.

   Users with CMKRNL privilege can change this parameter on a
   running system. Increasing the value of this parameter allows
   the global page table to expand, on demand, up to the maximum
   size.

   The default value is sufficient for the images normally installed
   as shared in the system startup command procedures. Once the
   system is running and all global sections are created, you can
   examine the actual requirements with the /GLOBAL qualifier of
   the Install utility (INSTALL) and reduce the value of GBLPAGES
   accordingly. However, do not set the value of this parameter
   too low, because the page table entries use little permanently
   resident memory. If you plan to install many user images as
   shared, or if user programs are likely to create many global
   sections, you must increase the value of this parameter.

   GBLPAGES has the AUTOGEN, DYNAMIC, FEEDBACK, GEN, and MAJOR
   attributes.
 

2  GBLPAGFIL
   GBLPAGFIL defines the maximum number of systemwide pages allowed
   for global page-file sections (scratch global sections that can
   be used without being mapped to a file). These global page-
   file sections can be temporary, permanent, system, or group,
   and are allocated from the page file specified in the system
   process header at bootstrap time. When you allow pages for
   global page-file sections, you must increase the size of the
   page file accordingly. Users with CMKRNL privilege can change
   this parameter value on a running system.

   Global page-file sections are created with the Create and Map
   Section system services ($CREATE_GPFILE, $CRMPSC, and $CRMPSC_
   GPFILE_64) without an explicit disk file. These sections are used
   for the RMS global buffers required for shared files. Users of
   shared files should note that global page-file sections cause
   both the global page table and the default system page file
   (PAGEFILE.SYS) to be used. If the value of GBLPAGFIL is too
   small, $CRMPSC issues an error message when you attempt to create
   global page-file sections.

   You must have scratch global sections if you use RMS global
   buffers. Each file using global buffers requires, in the system
   page file, the file's bucket size multiplied by the number of
   global buffers for that file. If the file's bucket size varies,
   as with RMS indexed files, use the maximum bucket size. For
   shared sequential files, use the multiblock count of the first
   stream to perform the $CONNECT service in place of the file's
   bucket size.

   The default value for this parameter is adequate for most
   systems. However, if your site uses RMS global buffering to a
   significant extent, you may need to raise the value of GBLPAGFIL.
   Use the /GLOBAL qualifier of the Install utility to examine
   the number of pages consumed by RMS global buffers. The global
   sections used by RMS for global buffers have the prefix RMS$
   followed by 8 hexadecimal digits.

   Global buffers are enabled with the DCL command SET
   FILE/GLOBAL_BUFFERS, which is described in the VSI OpenVMS DCL
   Dictionary.

   GBLPAGFIL is an AUTOGEN-altered and a DYNAMIC parameter.
 

2  GBLSECTIONS
   GBLSECTIONS sets the number of global section descriptors
   allocated in the system header at bootstrap time. Each global
   section requires one descriptor. Each descriptor takes 32 bytes
   of permanently resident memory.

   The default value is sufficient for the images normally installed
   as shared in the system startup command procedures. Once the
   system is running and all global sections are created, you can
   examine the actual requirements with the /GLOBAL qualifier of the
   Install utility and reduce the value of GBLSECTIONS accordingly.
   However, the value of this parameter should not be set too low.
   If you plan to install many user images as shared, or if user
   programs are likely to create many global sections, you must
   increase the value of this parameter.

   If the value of GBLSECTIONS is too small, you receive a message
   from the Install utility at system startup time or whenever
   you install images manually. Note that too large a value for
   GBLSECTIONS wastes physical memory.

   GBLSECTIONS has the AUTOGEN, FEEDBACK, GEN, and MAJOR attributes.
 

2  GB_CACHEALLMAX
   (Alpha and Integrity servers) If a file is connected to RMS with
   the RMS global buffer DEFAULT option enabled, the number of of
   blocks cached is either a maximum of the GB_CACHEALLMAX parameter
   or a percentage of the file, whichever results in a larger global
   count.

   Note that although a maximum cache size of %x7FFFFFFF is
   supported for an indexed file, sequential and relative file
   organizations are restricted to a maximum cache size of 32767.

   GB_CACHEALLMAX is a DYNAMIC parameter.
 

2  GB_DEFPERCENT
   (Alpha and Integrity servers) If a file is connected to RMS with
   the RMS global buffer DEFAULT option enabled, either a percentage
   (GB_DEFPERCENT) of the file is cached or up to GB_CACHEALLMAX
   blocks of it are cached, whichever results in a larger global
   buffer count. A percentage greater than 100 percent can be
   specified for GB_DEFPERCENT to provide growing room for a file
   in the global cache.

   Note that although a maximum cache size of %x7FFFFFFF is
   supported for an indexed file, sequential and relative file
   organizations are restricted to a maximum cache size of 32767.

   GB_DEFPERCENT is a DYNAMIC parameter.
 

2  GH_EXEC_CODE
   (Alpha and Integrity servers) GH_EXEC_CODE specifies the size in
   pages of the execlet code granularity hint region.

   GH_EXEC_CODE has the AUTOGEN and FEEDBACK attributes.
 

2  GH_EXEC_DATA
   (Alpha and Integrity servers) GH_EXEC_DATA specifies the size in
   pages of the execlet data granularity hint region.

   GH_EXEC_DATA has the AUTOGEN and FEEDBACK parameters.
 

2  GH_RES_CODE
   (Alpha and Integrity servers) GH_RES_CODE specifies the size in
   pages of the resident image code granularity hint region.

   GH_RES_CODE has the AUTOGEN and FEEDBACK attributes.
 

2  GH_RES_CODE_S2
   Specifies the size in pages of the resident 64-bit S2 space
   resident image code granularity hint region.
 

2  GH_RES_DATA
   (Alpha and Integrity servers) GH_RES_DATA specifies the size in
   pages of the resident image data granularity hint region.

   If bit 2 of the LOAD_SYS_IMAGES parameter is set, the image
   LDR$WRAPUP releases all unused pages in the granularity hint
   region at the the end of system startup. The unused pages of the
   resident image granularity hint region are either reserved for
   future use, or given back to the free memory list.

   GH_RES_DATA has the AUTOGEN and FEEDBACK attributes.
 

2  GH_RSRVPGCNT
   GH_RSRVPGCNT specifies the number of pages in the resident image
   code granularity hint region that the Install utility can use
   after the system has finished booting.

   If bit 2 of the LOAD_SYS_IMAGES parameter is set, the image
   LDR$WRAPUP releases all unused pages in the granularity hint
   region at the the end of system startup. The unused pages of the
   resident image granularity hint region are either reserved for
   future use, or given back to the free memory list.

   GH_RSRVPGCNT specifies the number of pages that LDR$WRAPUP
   attempts to leave in the resident image code granularity hint
   region. If the GH_RSRVPGCNT number of pages is larger than the
   unused pages in the granularity hint region, the region is not
   expanded to accommodate the number of pages requested.

   GH_RSRVPGCNT is a FEEDBACK attribute parameter.
 

2  GLX_INST_TMO
   (Alpha Galaxy platforms only) GLX_INST_TMO is the time (in
   milliseconds) that an instance in a Galaxy sharing set can fail
   to increment its timeout value before the other sharing instances
   presume that the instance failed and remove it from the sharing
   set.

   The default is 20,000 ms (20 seconds).
 

2  GLX_SHM_REG
   For Alpha Galaxy systems, GLX_SHM_REG is the number of shared
   memory region structures configured into the Galaxy Management
   Database (GMDB). If set to 0, the default number of shared memory
   regions are configured.

   If the condition value SS$_INSF_SHM_REG is returned for the
   $CRNMPSC_GDZRO_64 system service with the flag SEC$M_SHM_REG, the
   Galaxy shared memory code has run out of internal SHM_REG data
   structures. You need to increase the system parameter GLX_SHM_REG
   and reboot all Galaxy instances with this larger parameter value.
 

2  GROWLIM
   GROWLIM sets the number of pages that the system must have on the
   free-page list so that a process can add a page to its working
   set when it is above quota. GROWLIM has no effect if the process
   is below its working set quota. GROWLIM acts as a fast shutoff
   to the working set extent mechanism based on the system's free
   memory.

   GROWLIM has AUTOGEN, DYNAMIC, and MAJOR attributes.
 

2  IEEE_ADDRESS
   IEEE_ADDRESS is reserved for VSI use only.
 

2  IEEE_ADDRESSH
   IEEE_ADDRESSH is reserved for VSI use only.
 

2  IJOBLIM
   IJOBLIM sets the maximum number of interactive jobs that can be
   on the system concurrently. You can control the maximum number of
   concurrent interactive users on the system with the DCL command
   SET LOGINS/INTERACTIVE.

   IJOBLIM is a DYNAMIC parameter.
 

2  IMGIOCNT
   IMGIOCNT specifies the default number of pages of image I/O
   address space to be allocated for the image activator if not
   specified at program link time.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  IMGREG_PAGES
   (Alpha and Integrity servers) IMGREG_PAGES is the number of
   pages to reserve in P1 space for images to be installed with
   shareable address data. If IMGREG_PAGES is set to 0, no images
   are installed with shared address data. The default is 10,000
   pages.

   For more information, see the INSTALL section in the VSI OpenVMS
   System Management Utilities Reference Manual.
 

2  IO_PRCPU_BITMAP
   (Alpha and Integrity servers) This parameter is a bitmap
   representing up to 1024 CPUs. Each bit set in this bitmap
   indicates that the corresponding CPU is available for use as a
   Fast Path preferred CPU.

   IO_PRCPU_BITMAP defaults to all bits set. (CPU 0 through CPU 1023
   are all enabled for Fast Path port assignment.)

   You might want to disable the primary CPU from serving as a
   preferred CPU by leaving its bit clear in IO_PRCPU_BITMAP, which
   reserves the primary CPU for non-Fast Path IO operations to use.

   To change the value of IO_PRCPU_BITMAP in SYSBOOT or SYSGEN,
   specify a list of individual bits or contiguous groups of bits.
   For example:

      SYSGEN> SET IO_PRCPU_BITMAP 0,5,17-21

   This command sets bits 0, 5, 17, 18, 19, 20, and 21 in the bitmap
   and clears all other bits.

   Changing the value of IO_PRCPU_BITMAP causes the FASTPATH_SERVER
   process to run the automatic assignment algorithm that spreads
   Fast Path ports evenly among the new set of usable CPUs.

   For additional information, see FAST_PATH and FAST_PATH_PORTS.

   This parameter replaces IO_PREFER_CPU.
 

2  IOTA
   IOTA specifies the amount of time (in 10-millisecond units) to
   charge to the current residence quantum for each voluntary wait.
   The correct value approximates the cost of a disk I/O neglecting
   wait time.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  IRPCOUNT
   IRPCOUNT sets the number of preallocated intermediate request
   packets. Each packet requires 160 bytes of permanently resident
   memory. If IRPCOUNT is too large, physical memory is wasted.
   If IRPCOUNT is too small, the system increases its value
   automatically, as needed, to permit proper performance.
   However, the system cannot increase IRPCOUNT beyond the value
   of IRPCOUNTV.

   Allowing this growth causes a physical memory penalty. If
   IRPCOUNT is underconfigured, the penalty is 4 percent of physical
   memory from the configured value to the actual value on the
   running system.

   You can use the DCL command SHOW MEMORY/POOL/FULL to determine
   IRPCOUNT usage.

   IRPCOUNT has the GEN and MAJOR attributes.
 

2  IRPCOUNTV
   IRPCOUNTV establishes the upper limit to which IRPCOUNT can be
   automatically increased by the system.

   If this parameter is set too low, system performance can be
   adversely affected because IRPCOUNTV cannot be used for nonpaged
   pool requests.

   A physical memory penalty of 1 percent results for any unused
   growth space (1 longword for every 3 unused intermediate request
   packets).

   IRPCOUNTV has the GEN attribute.
 

2  JBOBLIM
   This parameter is no longer in use.
 

2  JOBCTLD
   System managers do not usually alter JOBCTLD; this word of debug
   flags is used in rolling upgrades of OpenVMS. If bit 0 is set,
   the queue manager does not start. The default is 0.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  KSTACKPAGES
   (Alpha and Integrity servers) KSTACKPAGES controls the number of
   pages allocated for process kernel stacks.
 

2  LAN_FLAGS
   (Alpha and Integrity servers) LAN_FLAGS is a bit mask used to
   enable features in the local area networks port drivers and
   support code. The default value for LAN_FLAGS is 0.

   The bit definitions are as follows:

   Bit        Description

   0          The default of zero indicates that ATM devices run in
              SONET mode. If set to 1, this bit indicates ATM devices
              run in SDH mode.

   1          If set, this bit enables a subset of the ATM trace
              and debug messages in the LAN port drivers and support
              code.

   2          If set, this bit enables all ATM trace and debug
              messages in the LAN port drivers and support code.

   3          If set, this bit runs UNI 3.0 over all ATM adapters.
              (Auto-sensing of the ATM UNI version is enabled if both
              bit 3 and bit 4 are off (0).)

   4          If set, this bit runs UNI 3.1 over all ATM adapters.
              (Auto-sensing of the ATM UNI version is enabled if both
              bit 3 and bit 4 are off (0).)

   5          If set, disables auto-negotiation over all Gigabit
              Ethernet Adapters.

   6          If set, enables the use of jumbo frames over all
              Gigabit Ethernet Adapters.

   7          Reserved.

   8          If set, disables the use of flow control over all LAN
              adapters that support flow control.

   9          Reserved.

   10         Reserved.

   11         If set, disables the logging of error log entries by
              LAN drivers.

   12         If set, enables a fast timeout on transmit requests,
              usually between 1 and 1.2 seconds instead of 3 to 4
              seconds, for most LAN drivers.

   13         If set, transmits that are given to the LAN device
              and never completed by the device (transmit timeout
              condition) are completed with error status (SS$_ABORT)
              rather than success status (SS$_NORMAL).

   LAN_FLAGS is a DYNAMIC parameter.
 

2  LCKMGR_CPUID
   (Alpha and Integrity servers) LCKMGR_CPUID controls the CPU that
   the Dedicated CPU Lock Manager runs on. This is the CPU that the
   LCKMGR_SERVER process utilizes if you turn this feature on with
   the LCKMGR_MODE system parameter.

   If the specified CPU ID is either the primary CPU or a
   nonexistent CPU, the LCKMGR_SERVER process utilizes the lowest
   nonprimary CPU. For more information, see the LCKMGR_MODE system
   parameter.

   LCKMGR_CPUID is a DYNAMIC parameter.
 

2  LCKMGR_MODE
   (Alpha and Integrity servers) The LCKMGR_MODE parameter controls
   use of the Dedicated CPU Lock Manager. Setting LCKMGR_MODE to a
   number greater than zero (0) indicates the number of CPUs that
   must be active before the Dedicated CPU Lock Manager is turned
   on.

   The Dedicated CPU Lock Manager performs all locking operations
   on a single dedicated CPU. This can improve system performance
   on large SMP systems with high MP_Synch associated with the lock
   manager.

   If the number of active CPUs is greater than or equal to LCKMGR_
   MODE, a LCKMGR_SERVER process is created to service locking
   operations. This process runs at a real-time priority of 63 and
   is always current.

   In addition, if the number of active CPUs should ever be reduced
   below the required threshold by either a STOP/CPU command or by
   a CPU reassignment in a Galaxy configuration, the Dedicated CPU
   Lock Manager automatically turns off within one second, and the
   LCKMGR_SERVER is placed in a hibernate state. If the number of
   active CPUs is increased, the LCKMGR_SERVER resumes servicing
   locking operations.

   Specify one of the following:

   o  Zero (0) indicates that the Dedicated CPU Lock Manager is off
      (the default).

   o  A number greater than zero (0) indicates the number of CPUs
      that must be active before the Dedicated CPU Lock Manager will
      turn on.

   When the Dedicated CPU Lock Manager is turned on, fast path
   devices are not assigned to the CPU used by the Dedicated CPU
   Lock Manager.

   When the Dedicated CPU Lock Manager is turned on, fast path
   devices are not assigned to the CPU used by the Dedicated CPU
   Lock Manager.

   For more information about use of the Dedicated CPU Lock Manager,
   see the OpenVMS Performance Management manual.

   LCKMGR_MODE is a DYNAMIC parameter.
 

2  LGI_BRK_DISUSER
   LGI_BRK_DISUSER turns on the DISUSER flag in the UAF record when
   an attempted break-in is detected, thus permanently locking
   out that account. The parameter is off (0)  by default. You
   should set the parameter (1)  only under extreme security watch
   conditions, because it results in severely restricted user
   service.

   LGI_BRK_DISUSER is a DYNAMIC parameter.
 

2  LGI_BRK_LIM
   LGI_BRK_LIM specifies the number of failures that can occur at
   login time before the system takes action against a possible
   break-in. The count of failures applies independently to login
   attempts by each user name, terminal, and node. Whenever login
   attempts from any of these sources reach the break-in limit
   specified by LGI_BRK_LIM, the system assumes it is under attack
   and initiates evasive action as specified by the LGI_HID_TIM
   parameter.

   The minimum value is 1. The default value is usually adequate.

   LGI_BRK_LIM is a DYNAMIC parameter.
 

2  LGI_BRK_TERM
   LGI_BRK_TERM causes the terminal name to be part of the
   association string for the terminal mode of break-in detection.
   When LGI_BRK_TERM is set to off (0), the processing considers
   the local or remote source of the attempt, allowing break-in
   detection to correlate failed access attempts across multiple
   terminal devices. When set to on (1), LGI_BRK_TERM assumes that
   only local hard-wired or dedicated terminals are in use and
   causes breakin detection processing to include the specific local
   terminal name when examining and correlating break-in attempts.

   Ordinarily, LGI_BRK_TERM should be set to off (0) when physical
   terminal names are created dynamically, such as when network
   protocols like LAT and Telnet are in use.

   LGI_BRK_TERM is a DYNAMIC parameter.
 

2  LGI_BRK_TMO
   LGI_BRK_TMO specifies the length of the failure monitoring
   period. This time increment is added to the suspect's expiration
   time each time a login failure occurs. Once the expiration period
   passes, prior failures are discarded, and the suspect is given a
   clean slate.

   LGI_BRK_TMO is a DYNAMIC parameter.
 

2  LGI_CALLOUTS
   LGI_CALLOUTS specifies the number of installation security policy
   callout modules to be invoked at each login. LGI_CALLOUTS must be
   set to 0 unless callout modules are present.

   LGI_CALLOUTS is a DYNAMIC parameter.
 

2  LGI_HID_TIM
   LGI_HID_TIM specifies the number of seconds that evasive action
   persists following the detection of a possible break-in attempt.
   The system refuses to allow any logins during this period, even
   if a valid user name and password are specified.

   LGI_HID_TIM is a DYNAMIC parameter.
 

2  LGI_PWD_TMO
   LGI_PWD_TMO specifies, in seconds, the period of time a user
   has to enter the correct system password (if used). LGI_PWD_TMO
   also establishes the timeout period for users to enter their
   personal account passwords at login time. Also, when using the
   SET PASSWORD command, LGI_PWD_TMO specifies the period of time
   the system waits for a user to type in a new password, an old
   password, and the password verification.

   LGI_PWD_TMO is a DYNAMIC parameter.
 

2  LGI_RETRY_LIM
   LGI_RETRY_LIM specifies the number of retry attempts allowed
   users attempting to log in. If this parameter is greater than 0,
   and a legitimate user fails to log in correctly because of typing
   errors, the user does not automatically lose the carrier. Instead
   (provided that LGI_RETRY_TMO has not elapsed), by pressing the
   Return key, the user is prompted to enter the user name and
   password again. Once the specified number of attempts has been
   made without success, the user loses the carrier. As long as
   neither LGI_BRK_LIM nor LGI_BRK_TMO has elapsed, the user can
   dial in again and reattempt login.

   LGI_RETRY_LIM is a DYNAMIC parameter.
 

2  LGI_RETRY_TMO
   LGI_RETRY_TMO specifies the number of seconds allowed between
   login retry attempts after each login failure. (Users can
   initiate login retries by pressing the Return key.) This
   parameter is intended to be used with the LGI_RETRY_LIM
   parameter; it allows dialup users a reasonable amount of time
   and number of opportunities to attempt logins before they lose
   the carrier.

   LGI_RETRY_TMO is a DYNAMIC parameter.
 

2  LNMPHASHTBL
   LNMPHASHTBL sets the size of the process logical name hash table.
   Logical names are hashed using a function of the name length
   and contents. The LNMPHASHTBL parameter determines the number
   of entries for process-private logical names. The recommended
   setting is the average number of process-private logical names.
   Note that the hashed values are rounded up to the nearest power
   of 2.

   LNMPHASHTBL has the GEN attribute. On VAX systems, LNMPHASHTBL is
   also an AUTOGEN-altered parameter.
 

2  LNMSHASHTBL
   LNMSHASHTBL sets the size of the system logical name hash table.
   Logical names are hashed using a function of the name length
   and contents. The LNMSHASHTBL parameter determines the number
   of entries for shareable logical names. These names include all
   names from the system, group, and job logical name tables. The
   recommended setting allows one to four logical names per hash
   table entry. The default setting is usually adequate, unless
   your installation has a large number of groups, or many jobs are
   active simultaneously. In that case, an increase in the value of
   the next higher power of 2 might improve logical name translation
   performance. Note that the hashed values are rounded up to the
   nearest power of 2.

   LNMSHASHTBL has the AUTOGEN, FEEDBACK, and GEN attributes.
 

2  LOAD_PWD_POLICY
   LOAD_PWD_POLICY controls whether the SET PASSWORD command
   attempts to use site-specific password policy routines, which
   are contained in the shareable image SYS$LIBRARY:VMS$PASSWORD_
   POLICY.EXE. The default is 0, which indicates not to use policy
   routines.
 

2  LOAD_SYS_IMAGES
   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   LOAD_SYS_IMAGES controls the loading of system images described
   in the system image data file, VMS$SYSTEM_IMAGES. This parameter
   is a bit mask.

   On Alpha and Integrity servers, the following bits are defined:

   Bit                         Description

   0 (SGN$V_LOAD_SYS_IMAGES)   Enables loading alternate execlets
                               specified in VMS$SYSTEM_IMAGES.DATA.

   1 (SGN$V_EXEC_SLICING)      Enables executive slicing.

   2 (SGN$V_RELEASE_PFNS)      Enables releasing unused portions of
                               the Alpha and Integrity servers huge
                               pages.

   These bits are on by default. Using conversational bootstrap exec
   slicing can be disabled.

   On Alpha and Integrity servers, LOAD_SYS_IMAGES is an AUTOGEN
   parameter.
 

2  LOCKDIRWT
   LOCKDIRWT determines the portion of lock manager directory that
   this system handles. The default value is usually adequate.

   LOCKDIRWT is an AUTOGEN parameter.
 

2  LOCKIDTBL
   LOCKIDTBL sets the initial number of entries in the system Lock
   ID table and defines the amount by which the Lock ID table is
   extended whenever the system runs out of locks. One entry must
   exist for each lock in the system; each entry requires 4 bytes.

   For simple timesharing systems, the default value is adequate.
   If your application uses many locks, as in the case of heavy RMS
   file sharing or a database management application, you should
   increase this parameter. When you change the value of LOCKIDTBL,
   examine the value of RESHASHTBL and change it if necessary.

   The OpenVMS Lock Management facility is described in the VSI
   OpenVMS Programming Concepts Manual. You can monitor locks with
   the MONITOR LOCK command of the Monitor utility.

   LOCKIDTBL has the AUTOGEN, FEEDBACK, and MAJOR attributes.
 

2  LOCKIDTBL_MAX
   LOCKIDTBL_MAX is obsolete beginning with OpenVMS Version 7.1.
 

2  LOCKRETRY
   LOCKRETRY establishes the number of attempts made to lock a
   multiprocessor data structure.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  LOCKRMWT

                                  NOTE

      On OpenVMS Version 8.3 systems, LOCKRMWT does not control
      lock remastering. See LOCKDIRWT.

   LOCKRMWT can have a value from zero to 10. The default is 5.
   Remaster decisions are based on the difference in lock remaster
   weights between the master and a remote node. When weights are
   equal, the remote node needs about 13% more activity before the
   tree is remastered. If a remote node has a higher lock remaster
   weight, the amount of activity is less. If the remote node has a
   lower lock remaster weight, the additional activity required to
   move the tree is much greater.

   Lock remaster weights of zero and 10 have additional meanings.
   A value of zero indicates that a node does not want to master
   trees and always remasters to an interested node with a higher
   LOCKRMWT. Lock trees on an interested node with a LOCKRMWT
   lower than 10 are remastered to the node with a weight of 10
   for LOCKRMWT.

   LOCKRMWT is a DYNAMIC parameter.
 

2  LONGWAIT
   LONGWAIT defines how much real time (in seconds) must elapse
   before the swapper considers a process to be temporarily idle.
   This parameter is applied to local event flag (LEF) and hibernate
   (HIB) waits to detect such conditions as an inactive terminal or
   ACP.

   LONGWAIT has the DYNAMIC, GEN, and MAJOR attributes. On Alpha
   and Integrity servers, LONGWAIT is also an AUTOGEN-altered
   parameter.
 

2  MAXBOBMEM
   (Alpha and Integrity servers) MAXBOBMEM defines the maximum
   amount of physical memory, measured in pagelets, that can be
   associated with a single buffer object created by a process
   in user mode. The default value of 0 means there is no system-
   imposed limit on the size of a buffer object.

   MAXBOBMEM is a DYNAMIC parameter.

   Other MAXBOB* parameters are obsolete beginning with OpenVMS
   Version 7.3.
 

2  MAXBUF
   MAXBUF sets the maximum allowable size for any single buffered
   I/O packet. Buffered I/O packets are allocated from the
   permanently resident nonpaged dynamic pool. The terminal,
   mailbox, and printer device drivers are examples of device
   drivers that perform buffered I/O.

   The number of bytes specified in the I/O request plus the size of
   a driver-dependent and function-dependent header area determine
   the required buffered I/O packet size. The size of the header
   area is a minimum of 16 bytes; there is no absolute upper limit.
   However, this header area is usually a few hundred bytes in size.

   The default value on Alpha and Integrity servers continues to be
   8192.

   The maximum value of MAXBUF is 64000 bytes.

   MAXBUF is a DYNAMIC parameter.
 

2  MAXCLASSPRI
   If class scheduling is enabled, MAXCLASSPRI sets the maximum
   range in the priority range of class-scheduled processes.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   MAXCLASSPRI is a DYNAMIC parameter.
 

2  MAXPROCESSCNT
   MAXPROCESSCNT sets the number of process entry slots allocated at
   bootstrap time. One slot is required for each concurrent process
   on the system. Each slot requires 6 bytes of permanently resident
   memory.

   The default value is normally configured to allow you to create
   the desired number of processes. If the following message
   appears, you need to increase the value of MAXPROCESSCNT:

   %SYSTEM-F-NOSLOT,  No PCB to create process

   On Alpha and Integrity servers beginning with Version 8.1, the
   default value is 32,767.

   MAXPROCESSCNT has the AUTOGEN, FEEDBACK, GEN, and MAJOR
   attributes.
 

2  MAXQUEPRI
   MAXQUEPRI determines the highest scheduling priority that can be
   assigned to jobs entered in batch and output (printer, server,
   and terminal) queues without the submitter process having OPER or
   ALTPRI privilege. The value of this parameter can range from 0 to
   255; the default is 100. The value of MAXQUEPRI should be greater
   than or equal to DEFQUEPRI.

                                  NOTE

      MAXQUEPRI refers to relative queue scheduling priority, not
      to the execution priority of the job.

   MAXQUEPRI is a DYNAMIC parameter.
 

2  MAXSYSGROUP
   MAXSYSGROUP sets the highest value that a group number can have
   and still be classified as a system UIC group number. Note that
   the specification is not in octal unless preceded by the %O radix
   indicator. This parameter is normally left at 8 (10 octal).

   MAXSYSGROUP is a DYNAMIC parameter.
 

2  MC_SERVICES_P0
   (Alpha only) MC_SERVICES_P0 controls whether other MEMORY CHANNEL
   nodes in the cluster continue to run if this node bugchecks or
   shuts down.

   A value of 1 causes other nodes in the MEMORY CHANNEL cluster to
   crash with bugcheck code MC_FORCED_CRASH if this node bugchecks
   or shuts down.

   The default value is 0. A setting of 1 is intended only for
   debugging purposes; the parameter should otherwise be left at
   its default value.

   MC_SERVICES_P0 is a DYNAMIC parameter.
 

2  MC_SERVICES_P1
   (Alpha only) This special parameter is reserved for VSI use. Its
   value must be the same on all nodes connected by MEMORY CHANNEL.

   MC_SERVICES_P1 is a DYNAMIC parameter.
 

2  MC_SERVICES_P2
   (Alpha only) MC_SERVICES_P2 specifies whether to load the
   PMDRIVER (PMA0) MEMORY CHANNEL cluster port driver.

   PMDRIVER is a driver that serves as the MEMORY CHANNEL cluster
   port driver. It works together with MCDRIVER (the MEMORY CHANNEL
   device driver and driver interface) to provide MEMORY CHANNEL
   clustering. If PMDRIVER is not loaded, cluster connections are
   not made over the MEMORY CHANNEL interconnect.

   The default value is 1, which causes PMDRIVER to be loaded when
   you boot the system. When you run CLUSTER_CONFIG.COM and select
   the MEMORY CHANNEL option, PMDRIVER is loaded automatically when
   you reboot the system.

   VSI recommends that this value not be changed. This parameter
   value must be the same on all nodes connected by MEMORY CHANNEL.
 

2  MC_SERVICES_P3
   (Alpha only) MC_SERVICES_P3 specifies the maximum number of tags
   supported. The maximum value is 2048, and the minimum value is
   100.

   The default value is 800. VSI recommends that this value not
   be changed. This parameter value must be the same on all nodes
   connected by MEMORY CHANNEL.

   MC_SERVICES_P3 is a DYNAMIC parameter.
 

2  MC_SERVICES_P4
   (Alpha only) MC_SERVICES_P4 specifies the maximum number of
   regions supported. The maximum value is 4096, and the minimum
   value is 100.

   The default value is 200. VSI recommends that this value not
   be changed. This parameter value must be the same on all nodes
   connected by MEMORY CHANNEL.
 

2  MC_SERVICES_P5
   (Alpha only) MC_SERVICES_P5 is reserved for VSI use only and must
   remain at the default value of 8000000. This value must be the
   same on all nodes connected by MEMORY CHANNEL.

   MC_SERVICES_P5 is a DYNAMIC parameter.
 

2  MC_SERVICES_P6
   (Alpha only) MC_SERVICES_P6 specifies MEMORY CHANNEL message
   size, the body of an entry in a free queue, or a work queue. The
   maximum value is 65536, and the minimum value is 544.

   The default value is 992. This value is suitable in all cases
   except for systems with highly constrained memory. For such
   systems, you can reduce the memory consumptions of MEMORY CHANNEL
   by slightly reducing the default value of 992. The value of MC_
   SERVICES_P6 must always be equal to or greater than the result of
   the following calculations:

   1. Select the larger of SCS_MAXMSG and SCS_MAXDG.

   2. Round that value up to the next quadword.

   The value of MC_SERVICES_P6 must be the same on all nodes
   connected by MEMORY CHANNEL.
 

2  MC_SERVICES_P7
   (Alpha only) MC_SERVICES_P7 specifies whether to suppress or
   display messages about MEMORY CHANNEL activities on this node.
   This parameter can be set to a value of 0, 1, or 2:

   o  A value of 0 indicates nonverbose mode: no informational
      messages appear on the console or in the error log.

   o  A value of 1 indicates verbose mode: informational messages
      from both MCDRIVER and PMDRIVER appear on the console and in
      the error log.

   o  A value of 2 provides the same output as a value of 1, with
      the addition of PMDRIVER stalling and recovery messages.

   The default value is 0. VSI recommends that this value not
   be changed except while debugging MEMORY CHANNEL problems or
   adjusting the MC_SERVICES_P9 parameter.

   MC_SERVICES_P7 is a DYNAMIC parameter.
 

2  MC_SERVICES_P8
   (Alpha only) MC_SERVICES_P8 is reserved for VSI use only and must
   remain at the default value of 0. The value must be the same on
   all nodes connected by MEMORY CHANNEL.
 

2  MC_SERVICES_P9
   (Alpha only) MC_SERVICES_P9 specifies the number of initial
   entries in a single channel's free queue. The maximum value is
   2048, and the minimum value is 10.

   Note that MC_SERVICES_P9 is not a dynamic parameter; you must
   reboot the system after each change for that change to take
   effect.

   The default value is 150. VSI recommends that this value not be
   changed.

   The value of MC_SERVICES_P9 must be the same on all nodes
   connected by MEMORY CHANNEL.
 

2  MINCLASSPRI
   If class scheduling is enabled, MINCLASSPRI sets the minimum
   range in the priority range of class-scheduled processes.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   MINCLASSPRI is a DYNAMIC parameter.
 

2  MINWSCNT
   The value specified by MINWSCNT is added to the size of the
   process header to establish the minimum working set size.

   On Alpha and Integrity servers, MINWSCNT sets the minimum number
   of pages required for the execution of a process. The default
   value is 20; the minimum value is 10.

   MINWSCNT is an AUTOGEN parameter.
 

2  MMG_CTLFLAGS
   MMG_CTLFLAGS is a bitmask used to enable or disable memory
   management-related activities.

   The first two bits, 0 and 1, control the proactive memory
   reclamation mechanisms. Bit 2 controls deferred memory testing.

   The following bit mask values are defined:

   Bit    Description

   0      If this bit is set, reclamation is enabled by trimming
          from periodically executing, but otherwise idle,
          processes. This occurs when the size of the free list
          plus the modified list drops below two times the value of
          FREEGOAL. This function is disabled if the bit is clear.

   1      If this bit is set, reclamation is enabled by outswapping
          processes that have been idle for longer than LONGWAIT
          seconds. This occurs when the size of the free list drops
          below FREEGOAL. This function is disabled if the bit is
          clear.

   2      Controls deferred memory testing (only on AlphaServer
          4100 systems). You can use this bit to speed up elapsed
          bootstrap time by controlling when memory is tested:

          o  If the bit is clear (the default), OpenVMS tests memory
             as a background activity, which might or might not
             complete before the end of the bootstrap process.

          o  If the bit is set, all memory is tested in the
             bootstrap process by the end of the EXEC_INIT phase
             (that is, before IPL is lowered from 31).

   3      Reserved to OpenVMS use; must be zero.

   4      If this bit is clear (the default), all page sizes
          supported by hardware can be used to map resident memory
          sections on Integrity servers. If this bit is set, page
          sizes on Integrity servers are limited to the maximum
          GH factor available on Alpha systems (512 * <system page
          size>).

   5-7    Reserved for future use.

   MMG_CTLFLAGS is an AUTOGEN and DYNAMIC parameter.
 

2  MOUNTMSG_(D)
   MOUNTMSG controls whether or not the messages that log volume
   mounts appear on the operator's terminal and in the operator's
   log. The default value of 0 disables reporting of these messages.
   This parameter does not control the messages generated by mount
   assistance requests.

   MOUNTMSG is a DYNAMIC parameter.
 

2  MPDEV_AFB_INTVL
   (Alpha and Integrity servers) MPDEV_AFB_INTVL specifies the
   automatic failback interval in seconds. The automatic failback
   interval is the minimum number of seconds that must elapse before
   the system attempts another failback from an MSCP path to a
   direct path on the same device.

   MPDEV_POLLER must be set to ON to enable automatic failback. You
   can disable automatic failback without disabling the poller by
   setting MPDEV_AFB_INTVL to 0. The default is 300 seconds.
 

2  MPDEV_D*
   (Alpha and Integrity servers) MPDEV_D1 through MPDEV_D4 are
   reserved for use by the operating system.
 

2  MPDEV_ENABLE
   (Alpha and Integrity servers) MPDEV_ENABLE enables the formation
   of multipath sets when set to ON (1).  If MPDEV_ENABLE is set
   to OFF (0),  the formation of additional multipath sets and the
   addition of new paths to existing multipath sets are disabled.
   However, existing multipath sets remain in effect. The default is
   ON.

   MPDEV_REMOTE and MPDEV_AFB_INTVL have no effect when MPDEV_ENABLE
   is set to OFF.
 

2  MPDEV_LCRETRIES
   (Alpha and Integrity servers) MPDEV_LCRETRIES controls the number
   of times the system retries the direct paths to the controller
   that the logical unit is online to, before moving on to direct
   paths to the other controller, or to an MSCP served path to the
   device. The valid range for retries is 1 through 256. The default
   is 1.
 

2  MPDEV_POLLER
   (Alpha and Integrity servers) MPDEV_POLLER enables polling of
   the paths to multipath set members when set to ON (1).  Polling
   allows early detection of errors on inactive paths. If a path
   becomes unavailable or returns to service, the system manager is
   notified with an OPCOM message. When set to OFF (0),  multipath
   polling is disabled. The default is ON. Note that this parameter
   must be set to ON to use the automatic failback feature.
 

2  MPDEV_REMOTE
   (Alpha and Integrity servers) MPDEV_REMOTE enables MSCP served
   paths to become members of a multipath set when set to ON (1).
   When set to OFF (0),  only local paths to a SCSI or Fibre Channel
   device is used in the formation of additional multipath sets.
   However, setting this parameter to OFF does not have any effect
   on existing multipath sets that have remote paths.

   To use multipath failover to a served path, MPDEV_REMOTE must
   be enabled on all systems that have direct access to shared
   SCSI/Fibre Channel devices. The first release to provide this
   feature is OpenVMS Alpha Version 7.3-1. Therefore, all nodes
   on which MPDEV_REMOTE is enabled must be running OpenVMS Alpha
   Version 7.3-1 (or later).

   If MPDEV_ENABLE is set to OFF (0), the setting of MPDEV_REMOTE
   has no effect because the addition of all new paths to multipath
   sets is disabled. The default is ON.
 

2  MPW_HILIMIT
   MPW_HILIMIT sets an upper limit for the modified-page list. When
   the list accumulates the number of pages specified by this limit,
   writing of the list begins. The pages that are written are then
   transferred to the free-page list.

   If MPW_HILIMIT is too low, excessive page faulting can occur from
   the page file. If it is too high, too many physical pages can be
   consumed by the modified-page list.

   If you increase MPW_HILIMIT, you might also need to increase
   MPW_WAITLIMIT. Note that if MPW_WAITLIMIT is less than
   MPW_HILIMIT, a system deadlock occurs. The values for the two
   parameters are usually equal.

   MPW_HILIMIT has the AUTOGEN and GEN attributes.
 

2  MPW_IOLIMIT
   MPW_IOLIMIT specifies the number of outstanding I/Os to the
   modified-page writer.

   On Alpha and Integrity servers, MPW_IOLIMIT is an AUTOGEN-altered
   parameter.
 

2  MPW_LOLIMIT
   MPW_LOLIMIT sets a lower limit for the modified-page list. When
   writing of the list causes the number of pages on the list to
   drop to or below this limit, writing stops.

   MPW_LOLIMIT ensures that a certain number of pages are available
   on the modified-page list for page faults. If the number is
   too small, the caching effectiveness of the modified-page list
   is reduced. If it is too high, less memory is available for
   processes, so that swap (and page) may increase.

   MPW_LOLIMIT has the AUTOGEN and GEN attributes.
 

2  MPW_LOWAITLIMIT
   MPW_LOWAITLIMIT specifies the threshold at which processes in
   the miscellaneous wait state MPWBUSY are allowed to resume.
   MPW_LOWAITLIMIT increases system performance for fast processors
   with large memories by reducing the amount of time processes
   spend in the MPWBUSY wait state.

   MPW_LOWAITLIMIT has the AUTOGEN and DYNAMIC attributes.
 

2  MPW_PRIO
   MPW_PRIO sets the priority of I/O transfers initiated by the
   modified page writer. The maximum value is 31, the minimum is 0,
   and the default is 4.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  MPW_THRESH
   MPW_THRESH sets a lower bound of pages that must exist on the
   modified-page list before the swapper writes this list to acquire
   free pages. If this requirement is met, the swapper tries to
   write the modified-page list rather than taking pages away from
   or swapping out a process.

   MPW_THRESH has the DYNAMIC attribute. On Alpha and Integrity
   servers, MPW_THRESH is also an AUTOGEN parameter.
 

2  MPW_WAITLIMIT
   MPW_WAITLIMIT sets the number of pages on the modified-page list
   that causes a process to wait until the next time the modified-
   page writer writes the modified list. This parameter limits the
   rate at which any single process can produce modified pages. If
   this value is less than MPW_HILIMIT, a system deadlock occurs.
   The value for this parameter is normally equal to MPW_HILIMIT.

   MPW_WAITLIMIT has the AUTOGEN and DYNAMIC attributes.
 

2  MPW_WRTCLUSTER
   MPW_WRTCLUSTER sets the number of pages to be written during one
   I/O operation from the modified-page list to the page file or
   a section file. The actual size of the cluster may be limited
   by the number of pages available for the I/O operation. This
   parameter can range in value from 16 to 120, in multiples of 8.
   Each page in the cluster requires 6 bytes of permanently resident
   memory.

   If MPW_WRTCLUSTER is too small, it takes many I/O operations
   to empty the modified-page list. If MPW_WRTCLUSTER is too large
   for the speed of the disk that holds the page file, other I/O
   operations are held up for the modified-page list write.

   On Alpha and Integrity servers, the MPW_WRTCLUSTER default value
   is 64 8192-byte pages; its maximum value is 512 8192-byte pages;
   and its minimum value is 16 8192-byte pages.

   MPW_WRTCLUSTER has the AUTOGEN and GEN attributes.
 

2  MSCP_BUFFER
   This buffer area is the space used by the server to transfer data
   between client systems and local disks.

   On Alpha and Integrity servers, MSCP_BUFFER specifies the number
   of pagelets to be allocated to the MSCP server's local buffer
   area.

   MSCP_BUFFER is an AUTOGEN and FEEDBACK parameter.
 

2  MSCP_CMD_TMO
   MSCP_CMD_TMO is the time in seconds that the OpenVMS MSCP server
   uses to detect MSCP command timeouts. The MSCP Server must
   complete the command within a built-in time of approximately
   40 seconds plus the value of the MSCP_CMD_TMO parameter.

   The MSCP_CMD_TMO default value of 0 is normally adequate. A
   value of 0 provides the same behavior as in previous releases
   of OpenVMS (which did not have an MSCP_CMD_TMO system parameter).
   A nonzero setting increases the amount of time before an MSCP
   command times out.

   If command timeout errors are being logged on client nodes,
   setting the parameter to a nonzero value on OpenVMS servers
   may reduce the number of errors logged. As the value of the
   MSCP_CMD_TMO increases, the number of client MSCP command timeouts
   will decrease, at the cost of increased time to detect a faulty
   MSCP controller or MSCP-served device.

   If you need to decrease the number of command timeout errors, VSI
   recommends that you set an initial value of 60. If timeout errors
   continue to be logged, you can increase this value in increments
   of 20 seconds.

   MSCP_CMD_TMO is a DYNAMIC parameter.
 

2  MSCP_CREDITS
   MSCP_CREDITS specifies the number of outstanding I/O requests
   that can be active from one client system.

   The default value is currently 32. Unless a system has very
   constrained memory available, VSI recommends that these values
   not be increased.
 

2  MSCP_LOAD
   MSCP_LOAD controls the loading of the MSCP server during a system
   boot. Specify one of the following values:

   Value  Description

   0      Do not load the MSCP server. This is the default value.

   1      Load the MSCP server and serve disks as specified by the
          MSCP_SERVE_ALL parameter.

   MSCP_LOAD has the AUTOGEN attribute.
 

2  MSCP_SERVE_ALL
   MSCP_SERVE_ALL is a bit mask that controls disk serving in an
   OpenVMS Cluster. A disk is served regardless of its allocation
   class unless bit 3 has a value of 1.

   Starting with OpenVMS Version 7.2, the serving types are
   implemented as a bit mask. To specify the type of serving your
   system will perform, locate the type you want in the following
   table and specify its value. For some systems, you may want to
   specify two serving types, such as serving the system disk and
   serving locally attached disks. To specify such a combination,
   add the values of each type, and specify the sum.

   In a mixed-version cluster that includes any systems running
   OpenVMS Version 7.1-x or earlier, serving all available disks
   is restricted to serving all disks except those whose allocation
   class does not match the system's node allocation class (prior
   to Version 7.2). To specify this type of serving, use the value 9
   (which sets bit 0 and bit 3).

   The following table describes the serving type controlled by each
   bit and its decimal value:

   Bit and
   Value
   When Set      Description

   Bit 0 (1)     Serve all available disks (locally attached and
                 those connected to HSx and DSSI controllers).
                 Disks with allocation classes that differ from
                 the system's allocation class (set by the ALLOCLASS
                 parameter) are also served if bit 3 is not set.

   Bit 1 (2)     Serve locally attached (non-HSx and DSSI) disks.

   Bit 2 (4)     Serve the system disk. This is the default setting.
                 This setting is important when other nodes in the
                 cluster rely on this system being able to serve
                 its system disk. This setting prevents obscure
                 contention problems that can occur when a system
                 attempts to complete I/O to a remote system disk
                 whose system has failed.

   Bit 3 (8)     Restrict the serving specified by bit 0. All disks
                 except those with allocation classes that differ
                 from the system's allocation class (set by the
                 ALLOCLASS parameter) are served.

                 This is pre-Version 7.2 behavior. If your cluster
                 includes systems running OpenVMS 7.1-x or earlier,
                 and you want to serve all available disks, you must
                 specify 9, the result of setting this bit and bit
                 0.

   Although the serving types are now implemented as a bit mask, the
   values of 0, 1, and 2, specified by bit 0 and bit 1, retain their
   original meanings:

      0 - Do not serve any disks (the default for earlier versions
      of OpenVMS).

      1 - Serve all available disks.


      2 - Serve only locally attached (non-HSx and non-DSSI) disks.

   If the MSCP_LOAD system parameter is 0, MSCP_SERVE_ALL is
   ignored.
 

2  MULTIPROCESSING
   MULTIPROCESSING controls the loading of the system
   synchronization image.

   Specify one of the following values:

   Value    Description

   0        Load the uniprocessing synchronization image
            SYSTEM_SYNCHRONIZATION_UNI.EXE.

   1        If the CPU type is capable of SMP and two or
            more CPUs are present on the system, load the
            full-checking multiprocessing synchronization
            image SYSTEM_SYNCHRONIZATION.EXE. Otherwise,
            load the uniprocessing synchronization image
            SYSTEM_SYNCHRONIZATION_UNI.EXE.

   2        Always load the full-checking version
            SYSTEM_SYNCHRONIZATION.EXE, regardless of system
            configuration or CPU availability.

   3        If the CPU type is capable of SMP and two or more
            CPUs are present on the system, load the optimized
            streamlined multiprocessing image:

            o  On Alpha and Integrity servers, this image is
               SYSTEM_SYNCHRONIZATION_MIN.EXE.

            Otherwise, load the uniprocessing synchronization image
            SYSTEM_SYNCHRONIZATION_UNI.EXE. The default value is 3.

   4        Always load the streamlined multiprocessing image
            SYSTEM_SYNCHRONIZATION_MIN.EXE, regardless of system
            configuration or CPU availability.

   Setting the SYSTEM_CHECK parameter to 1 has the effect of setting
   MULTIPROCESSING to 2.
 

2  MULTITHREAD
   MULTITHREAD controls the availability of kernel threads
   functions. Specify one of the following values:

   Value            Description

   0                Both Thread Manager upcalls and the creation of
                    multiple kernel threads are disabled.

   1                Thread Manager upcalls are enabled; the creation
                    of multiple kernel threads is disabled.

   2-256 (Alpha     Both Thread Manager upcalls and the creation
   and Integrity    of multiple kernel threads are enabled. The
   servers)         number specified represents the maximum number
                    of kernel threads that can be created for a
                    single process.

   The maximum value for MULTITHREAD is 256.

   MULTITHREAD is an AUTOGEN and DYNAMIC parameter.
 

2  MVSUPMSG_INTVL
   (Alpha and Integrity servers) The system suppresses mount
   verification start and end messages for fibre channel disk
   devices if mount verification completes on the first attempt
   and if mount verification does not occur too often. MVSUPMSG_NUM
   and this parameter establish this limit.

   The system issues a mount verification message after a sequence
   of MVSUPMSG_NUM mount verifications have gone unannounced on a
   specific fibre channel disk device within a span of MVSUPMSG_
   INTVL seconds.

   If this parameter is zero, all mount verification messages are
   announced.

   MVSUPMSG_INTVL is a DYNAMIC parameter.
 

2  MVSUPMSG_NUM
   (Alpha and Integrity servers) The system suppresses mount
   verification start and end messages for fibre channel disk
   devices if mount verification completes on the first attempt and
   if mount verification does not occur too often. MVSUPMSG_INTVL
   and this parameter establish this limit.

   The system issues a mount verification message after a sequence
   of MVSUPMSG_NUM mount verifications have gone unannounced on a
   specific fibre channel disk device within a span of MVSUPMSG_
   INTVL seconds.

   If this parameter is zero, all mount verification messages are
   announced.

   MVSUPMSG_NUM is a DYNAMIC parameter.
 

2  MVTIMEOUT
   MVTIMEOUT is the time in seconds that a mount verification
   attempt continues on a given disk volume. If the mount
   verification does not recover the volume within that time, the
   I/O operations outstanding to the volume terminate abnormally.

   MVTIMEOUT is a DYNAMIC parameter. On Alpha and Integrity servers,
   MVTIMEOUT is also an AUTOGEN parameter.
 

2  NET_CALLOUTS
   NET_CALLOUTS is normally set to 0. A value of 255 indicates that
   no attempt is to be made to assign a new proxy connection to an
   active server, but that a new process must be started to invoke
   the installation security policy callout modules in LOGINOUT.EXE.
   Values 1 through 254 are reserved for future use.

   NET_CALLOUTS is a DYNAMIC parameter.
 

2  NISCS_CONV_BOOT
   NISCS_CONV_BOOT controls whether a conversational boot is
   permitted during a remote system boot. The default value of 0
   specifies that conversational boots are not permitted.
 

2  NISCS_LOAD_PEA0
   NISCS_LOAD_PEA0 controls whether the NI-SCS port driver PEDRIVER
   is loaded during system boot. The default of 0 specifies that the
   PEDRIVER is not loaded.
 

2  NISCS_MAX_PKTSZ
   This parameter specifies an upper limit on the size, in bytes,
   of the user data area in the largest packet sent by NISCA on any
   local area network (LAN).

   NISCS_MAX_PKTSZ allows the system manager to change the packet
   size used for cluster communications on network communication
   paths. PEDRIVER automatically allocates memory to support
   the largest packet size that is usable by any virtual circuit
   connected to the system up to the limit set by this parameter. On
   Alpha and Integrity servers, to optimize performance, the default
   value is the largest packet size currently supported by OpenVMS.

   PEDRIVER uses NISCS_MAX_PKTSZ to compute the maximum amount of
   data to transmit in any LAN packet:

   LAN packet size <= LAN header (padded Ethernet format)
                      + NISCS_MAX_PKTSZ
                      + NISCS checksum (only if data checking
                                        is enabled)
                      + LAN CRC or FCS

   The actual packet size automatically used by PEDRIVER might be
   smaller than the NISCS_MAX_PKTSZ limit for any of the following
   reasons:

   o  On a per-LAN path basis, if PEdriver determines that the LAN
      path between two nodes, including the local and remote LAN
      adapters and intervening LAN equipment, can only convey a
      lesser size.

      In other words, only nodes with large-packet LAN adapters
      connected end-to-end by large-packet LAN equipment can use
      large packets. Nodes connected to large-packet LANs but having
      an end-to-end path that involves an Ethernet segment restrict
      packet size to that of an Ethernet packet (1498 bytes).

   o  For performance reasons, PEDRIVER might further limit
      the upper bound on packet size so that the packets can be
      allocated from a lookaside list in the nonpaged pool.

   The actual memory allocation includes the required data structure
   overhead used by PEDRIVER and the LAN drivers, in addition to the
   actual LAN packet size.

   The following table shows the minimum NISCS_MAX_PKTSZ value
   required to use the maximum packet size supported by specified
   LAN types:

   Type of LAN           Minimum Value for NISCS_MAX_PKTSZ

   Ethernet              1498

   FDDI                  4382 (before Version 7.3)
                         4396 (Version 7.3 and later)

   Gigabit Ethernet      8192

   ATM                   7606

   Note that the maximum packet size for some Gigabit Ethernet
   adapters is larger than the maximum value of NISCS_MAX_PKTSZ
   (8192 bytes). See the LAN_FLAGS parameter for a description of
   how to enable jumbo frames on Gigabit Ethernet-that is, packet
   sizes larger than those noted for Ethernet.

   On Alpha and Integrity servers, NISCS_MAX_PKTSZ is an AUTOGEN
   parameter.
 

2  NISCS_PORT_SERV
   NISCS_PORT_SERV provides flag bits for PEDRIVER port services:

   o  Setting bits 0 and 1 (hex bitmask value 3) enables data
      checking.

   o  Setting bit 2 (hex bitmask value 4) enables data compression
      on all virtual channels (VCs) to nodes that support
      compression.

   The remaining bits are reserved for future use.

   Starting with OpenVMS Version 7.3-1, you can use the SCACP
   command SET VC/CHECKSUMMING to specify data checking on the VCs
   to certain nodes. You can do this on a running system. (For more
   information, see the SCACP documentation in the VSI OpenVMS System
   Management Utilities Reference Manual.

   Starting with OpenVMS Version 8.3, you can also use the SCACP
   command SET VC/COMPRESSION to specify data compression on the
   on the VCs to certain nodes. You can use SCACP to enable either
   data checking or data compression on a running system. (See the
   SCACP documentation in the the VSI OpenVMS System Management
   Utilities Reference Manual for more information. Also starting
   with OpenVMS Version 8.3, the NISCS_PORT_SERV system parameter
   is dynamic, that is, changing the setting of this parameter no
   longer requires a reboot. Furthermore, this parameter applies
   to all virtual circuits between the node on which it is set and
   other nodes in the cluster.

   NISCS_PORT_SERV has the DYNAMIC and AUTOGEN attributes.
 

2  NOAUTOCONFIG
   NOAUTOCONFIG controls whether all devices are automatically
   configured when the system boots. The default value of 0 sets the
   system to automatically configure all devices. Set NOAUTOCONFIG
   to 1 (no automatic configuration) only for debugging purposes.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   NOAUTOCONFIG is a DYNAMIC parameter.
 

2  NOCLUSTER
   NOCLUSTER controls whether page read clustering is inhibited
   when the system boots. Set NOCLUSTER to 1 (inhibit page read
   clustering) only for debugging purposes.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  NOPGFLSWP
   If enabled, NOPGFLSWP disables swapping into page files.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  NPAGECALC
   NPAGECALC controls whether the system automatically calculates
   the initial size for nonpaged dynamic memory.

   VSI sets the default value of NPAGECALC to 1 only during the
   initial boot after an installation or upgrade. When the value
   of NPAGECALC is 1, the system calculates an initial value for the
   NPAGEVIR and NPAGEDYN system parameters. This calculated value is
   based on the amount of physical memory in the system.

   NPAGECALC's calculations do not reduce the values of NPAGEVIR and
   NPAGEDYN from the values you see or set at the SYSBOOT prompt.
   However, NPAGECALC's calculation might increase these values.

   AUTOGEN sets NPAGECALC to 0. NPAGECALC should always remain 0
   after AUTOGEN has determined more refined values for the NPAGEDYN
   and NPAGEVIR system parameters.
 

2  NPAGEDYN
   NPAGEDYN sets the size of the nonpaged dynamic pool in bytes.
   This figure is rounded down to an integral number of pages.
   NPAGEDYN establishes the initial setting of the nonpaged pool
   size, but the pool size can be increased dynamically.

   To set a value for this parameter, use AUTOGEN initially, and
   then monitor the amount of space actually used with the DCL
   command SHOW MEMORY/POOL/FULL.

   For the benefit of OpenVMS VAX systems with limited physical
   memory, AUTOGEN logs a warning message in its report if NPAGEDYN
   exceeds 10 percent of physical memory or if NPAGEVIR exceeds 33
   percent of physical memory.

   AUTOGEN also limits its own calculated value for NPAGEDYN to
   20 percent of physical memory and limits NPAGEVIR to 50 percent
   of physical memory. These calculated values are adequate for
   most workstations and systems with 16 or fewer megabytes of
   physical memory. If your system requires a larger value, you can
   override the AUTOGEN calculated values by setting higher values
   in MODPARAMS.DAT.

   NPAGEDYN has AUTOGEN, FEEDBACK, GEN, and MAJOR attributes.
 

2  NPAGERAD
   (Alpha and Integrity servers) NPAGERAD specifies the total number
   of bytes of nonpaged pool that will be allocated for Resource
   Affinity Domains (RADs) other than the base RAD. For platforms
   that have no RADs, NPAGERAD is ignored. Notice that NPAGEDYN
   specifies the total amount of nonpaged pool for all RADs.

   Also notice that the OpenVMS system might round the specified
   values higher to an even number of pages for each RAD, which
   prevents the base RAD from having too little nonpaged pool. For
   example, if the hardware is an AlphaServer GS160 with 4 RADs:

   NPAGEDYN = 6291456 bytes
   NPAGERAD = 2097152 bytes

   In this case, the OpenVMS system allocates a total of
   approximately 6,291,456 bytes of nonpaged pool. Of this amount,
   the system divides 2,097,152 bytes among the RADs that are not
   the base RAD. The system then assigns the remaining 4,194,304
   bytes to the base RAD.

                                  NOTE

      The system actually rounds up to an even number of pages
      on each RAD. In addition, the base RAD is never assigned a
      value less than the smaller of the value of NPAGEDYN and 4
      megabytes.

   On AlphaServer GS series processors on OpenVMS systems prior to
   Version 7.3-1, system managers frequently saw pool expansion that
   increasing NPAGEDYN did not reduce. This problem was caused by
   leaving NPAGERAD at its default value of 0.

   Starting with OpenVMS Version 7.3-1, when NPAGERAD is 0 (the
   default), the system calculates a value to use for NPAGERAD with
   the following formula:

                     Base RAD memory
      NPAGEDYN * (1- --------------- )
                      Total memory

   This calculation gives more pool to the non-base RADs than before
   and, therefore, reduces the expansion of non-base RADs.

   NPAGERAD has the GEN attribute.
 

2  NPAGEVIR
   NPAGEVIR defines the maximum size to which NPAGEDYN can be
   increased. If this value is too small, the system can hang.
   If NPAGEVIR is too large, the result is a penalty of 4 bytes
   per extra page on VAX and 8 bytes per extra page on Alpha and
   Integrity servers.

   For the benefit of OpenVMS VAX systems with limited physical
   memory, AUTOGEN logs a warning message in its report if NPAGEDYN
   exceeds 10 percent of physical memory or if NPAGEVIR exceeds 33
   percent of physical memory.

   AUTOGEN also limits its own calculated value for NPAGEDYN to 20
   percent of physical memory, and limits NPAGEVIR to 50 percent
   of physical memory. These calculated values are adequate for
   most workstations and systems with 16 or fewer megabytes of
   physical memory. If your system requires a larger value, you can
   override the AUTOGEN calculated values by setting higher values
   in MODPARAMS.DAT.

   NPAGEVIR has AUTOGEN and GEN attributes.
 

2  NPAG_AGGRESSIVE
   Beginning with OpenVMS Version 8.2, the default values of NPAG_
   AGGRESSIVE and NPAG_GENTLE are 100. A value of 100 turns off
   both gentle and aggressive reclamation of nonpaged pool lookaside
   lists. In many cases, when pool reclamation moves small packets
   from the lookaside lists back to the variable list, the result
   is fragmentation of the variable list. This fragmentation appears
   as many small packets at the front of the variable list and a few
   large packets at the end of the list.

   When an allocation occurs for a packet that is larger than any
   of the lookaside lists, the system must find a large enough
   packet on the variable list. When heavily fragmented, the entire
   variable list often must be searched to find a large enough
   packet. Because the variable list is kept in address order, when
   a large packet is deallocated, the entire list must be searched
   again to deallocate the packet.

   Under these conditions, system performance can be severely
   degraded. For this reason, VSI recommends that you turn off pool
   reclamation but keep both NPAG_AGGRESSIVE and NPAG_GENTLE system
   parameters set to 100.

   NPAG_AGGRESSIVE is a DYNAMIC parameter.
 

2  NPAG_BAP_MAX
   (Alpha and Integrity servers) NPAG_BAP_MAX is the size in bytes
   of the bus addressable pool (BAP) that the system creates under
   normal circumstances.

   See also NPAG_BAP_MIN.
 

2  NPAG_BAP_MAX_PA
   (Alpha and Integrity servers) NPAG_BAP_MAX_PA is the highest
   physical address in megabytes that is allowed in bus addressable
   pool (BAP).
 

2  NPAG_BAP_MIN
   (Alpha and Integrity servers) NPAG_BAP_MIN is the size in bytes
   of the bus addressable pool (BAP) that the system creates when
   memory resources are unusually constrained.
 

2  NPAG_BAP_MIN_PA
   (Alpha and Integrity servers) NPAG_BAP_MIN_PA specifies the
   lowest physical address in megabytes that is allowed in bus
   addressable pool (BAP).
 

2  NPAG_GENTLE
   Beginning with Version 8.2, the default values of NPAG_AGGRESSIVE
   and NPAG_GENTLE are 100. A value of 100 turns off both gentle
   and aggressive reclamation of nonpaged pool lookaside lists.
   In many cases, when pool reclamation moves small packets from
   the lookaside lists back to the variable list, the result is
   fragmentation of the variable list. This fragmentation appears
   as many small packets at the front of the variable list and a few
   large packets at the end of the list.

   When an allocation occurs for a packet that is larger than any
   of the lookaside lists, the system must find a large enough
   packet on the variable list. When heavily fragmented, the entire
   variable list often must be searched to find a large enough
   packet. Because the variable list is kept in address order, when
   a large packet is deallocated, the entire list must be searched
   again to deallocate the packet.

   Under these conditions, system performance can be severely
   degraded. For this reason, VSI recommends that you turn off pool
   reclamation but keep both NPAG_AGGRESSIVE and NPAG_GENTLE system
   parameters set to 100.

   NPAG_GENTLE is a DYNAMIC parameter.
 

2  NPAG_INTERVAL
   NPAG_INTERVAL is the number of seconds between passes of
   nonpaged-pool gentle reclamation.

   NPAG_INTERVAL is a DYNAMIC parameter.
 

2  NPAG_RING_SIZE
   NPAG_RING_SIZE represents the number of entries in the ring
   buffer.
 

2  PAGED_LAL_SIZE
   PAGED_LAL_SIZE sets the maximum size, in bytes, to use for the
   page dynamic pool lookaside lists. Use of these lookaside lists
   can reduce paged dynamic pool variable freelist fragmentation and
   improve paged pool allocation and deallocation performance.

   By default, PAGED_LAL_SIZE is set to 0, which disables the use of
   the paged dynamic pool lookaside lists.

   For environments experiencing paged pool variable freelist
   fragmentation a modest PAGED_LAL_SIZE, 512, has been adequate
   to improve paged pool performance and reduce fragmentation. If
   this parameter is made large and later decreased in size, some
   paged pool packets can be left unused until the parameter is made
   larger again, or the lookaside lists are reclaimed from due to a
   paged pool shortage. The paged dynamic pool lookaside lists will
   not occupy more than three-quarters of the available paged pool.

   PAGED_LAL_SIZE has DYNAMIC, GEN, and MAJOR attributes.
 

2  PAGFILCNT
   On Alpha and Integrity servers, beginning in OpenVMS Version 7.3,
   this parameter is obsolete.

   PAGFILCNT has the GEN attribute on VAX systems.
 

2  PAGTBLPFC
   PAGTBLPFC specifies (in pages) the maximum number of page tables
   to read to satisfy a fault for a nonresident page table.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  PAMAXPORT
   PAMAXPORT specifies the maximum port number to be polled on each
   CI and DSSI. The CI and DSSI port drivers poll to discover newly
   initialized ports or the absence/failure of previously responding
   remote ports.

   A system does not detect the existence of ports whose port
   numbers are higher than this parameter's value. Thus, set this
   parameter to a value that is equal to or greater than the highest
   port number being used on any CI or DSSI connected to the system.

   You can decrease this parameter to reduce polling activity if
   the hardware configuration has fewer than 16 ports. For example,
   if the CI or DSSI with the largest configuration has a total
   of 5 ports assigned to port numbers 0 through 4, you could set
   PAMAXPORT to 4.

   If CI or DSSI devices are not configured on your system, this
   parameter is ignored.

   The default for this parameter is 15 (poll for all possible ports
   0 through 15). VSI recommends that you set this parameter to the
   same value on each cluster computer.

   PAMAXPORT is a DYNAMIC parameter.
 

2  PANOPOLL
   Disables CI and DSSI polling for ports if set to 1. (The default
   is 0.) When PANOPOLL is set, a computer does not discover that
   another computer has shut down or powered down promptly and does
   not discover a new computer that has booted. This parameter is
   useful when you want to bring up a computer detached from the
   rest of the cluster for checkout purposes.

   PANOPOLL is functionally equivalent to uncabling the system from
   the DSSI or star coupler. This parameter does not affect OpenVMS
   Cluster communications by LAN.

   The default value of 0 is the normal setting and is required
   if you are booting from an HSC controller or if your system is
   joining an OpenVMS Cluster. This parameter is ignored if no CI or
   DSSI devices are configured on your system.

   PANOPOLL is a DYNAMIC parameter.
 

2  PANUMPOLL
   PANUMPOLL establishes the number of CI and DSSI ports to be
   polled each polling interval. The normal setting for PANUMPOLL
   is 16.

   On systems with less powerful CPUs, the parameter may be useful
   in applications sensitive to the amount of contiguous time that
   the system spends at IPL 8. Reducing PANUMPOLL reduces the amount
   of time spent at IPL 8 during each polling interval, while
   increasing the number of polling intervals needed to discover
   new or failed ports.

   If CI or DSSI devices are not configured on your system, this
   parameter is ignored.

   PANUMPOLL is a DYNAMIC parameter.
 

2  PAPOLLINTERVAL
   Specifies, in seconds, the polling interval the CI port driver
   uses to poll for a newly booted computer, a broken port-to-port
   virtual circuit, or a failed remote computer.

   This parameter trades polling overhead against quick response to
   virtual circuit failures. VSI recommends that you use the default
   value for this parameter.

   VSI recommends that you set this parameter to the same value on
   each cluster computer.

   PAPOLLINTERVAL is a DYNAMIC parameter.
 

2  PAPOOLINTERVAL
   Specifies, in seconds, the interval at which the port driver
   checks available nonpaged pool after a pool allocation failure.

   This parameter trades faster response to pool allocation failures
   against increased polling overhead. VSI recommends that you use
   the default value for this parameter.

   If CI or DSSI devices are not configured on your system, this
   parameter is ignored.

   PAPOOLLINTERVAL is a DYNAMIC parameter.
 

2  PASANITY
   PASANITY controls whether the CI and DSSI port sanity timers are
   enabled to permit remote systems to detect a system that has been
   hung at IPL 8 or above for 100 seconds. It also controls whether
   virtual circuit checking gets enabled on the local system. The
   TIMVCFAIL parameter controls the time (1-99 seconds).

   PASANITY is normally set to 1 and should be set to 0 only when
   you are debugging with XDELTA or planning to halt the CPU for
   periods of 100 seconds or more.

   PASANITY is only semidynamic. A new value of PASANITY takes
   effect on the next CI or DSSI port reinitialization.

   If CI or DSSI devices are not configured on your system, this
   parameter is ignored.
 

2  PASTDGBUF
   The number of datagram receive buffers to queue initially for the
   cluster port driver's configuration poller. The initial value is
   expanded during system operation, if needed.

   Memory Channel devices ignore this parameter.

   PASTDGBUF is an AUTOGEN parameter.
 

2  PASTIMOUT
   The basic interval at which the CI port driver wakes up to
   perform time-based bookkeeping operations. It is also the period
   after which a timeout is declared if no response to a start
   handshake datagram has been received.

   If CI or DSSI devices are not configured on your system, this
   parameter is ignored.

   The default value should always be adequate.

   PASTIMOUT is a DYNAMIC parameter.
 

2  PE1-6
   PE1, PE2, PE3, PE4, PE5, PE6 are reserved for VSI use only. These
   parameters are for cluster algorithms and their usages can change
   from release to release. VSI recommends using the default values
   for these special parameters.
 

2  PFCDEFAULT
   On Alpha and Integrity servers during execution of programs,
   PFCDEFAULT controls the number of image pagelets read from
   disk per I/O operation when a page fault occurs. The PFCDEFAULT
   maximum default value is 2032 512-byte pagelets (127 8192-byte
   Alpha and Integrity server pages).

   The read I/O operations can take place from an image file or
   from the page file. The actual size of the cluster can be less
   than PFCDEFAULT, depending on the size of image sections and the
   pattern of page references.

   The value should not be greater than one-fourth the default size
   of the average working set to prevent a single page fault from
   displacing a major portion of a working set. Too large a value
   for PFCDEFAULT can hurt system performance. PFCDEFAULT can be
   overridden on an image-by-image basis with the CLUSTER option of
   the OpenVMS linker.

   PFCDEFAULT has the AUTOGEN and DYNAMIC attributes.
 

2  PFN_COLOR_COUNT
   (Alpha and Integrity servers) PFN_COLOR_COUNT specifies the
   number of buckets (colors) into which all members of the zeroed
   page list and all unencumbered members of the free page list are
   sorted. OpenVMS Alpha systems might derive a preferred page color
   from a request to map a given virtual page and attempt to map
   that virtual page to a PFN of matching "color." This results in
   less variance in which cache blocks are used when accessing that
   page. This might or might not improve performance, depending on
   the application.

   This special parameter is use by VSI and is subject to change.
   Do not change this parameter unless VSI recommends that you do so.
   If you increase this parameter, you must also increase the ZERO_
   LIST_HI system parameter.
 

2  PFRATH
   PFRATH specifies the page fault rate above which the limit of
   a working set is automatically increased. The unit of measure
   is the number of faults per 10 seconds of processor time. At a
   setting of 120, for example, the system automatically increases
   the limit of a working set if it is faulting more than 120 pages
   per 10 seconds. Decreasing the value of this parameter tends to
   increase the limits of the working sets, while increasing its
   value tends to decrease their limits.

   On Alpha and Integrity servers, the default value is 8 page
   faults every 10 seconds.

   PFRATH has the DYNAMIC and MAJOR attributes. On Alpha and
   Integrity servers, PFRATH also is an AUTOGEN-altered parameter.
 

2  PFRATL
   PFRATL specifies the page fault rate below which the limit of
   a working set is automatically decreased. The unit of measure
   is the number of faults per 10 seconds of processor time. At a
   setting of 1, for example, the system automatically decreases the
   limit of a working set if it is faulting less than 1 page every
   10 seconds.

   Increasing the value of this parameter tends to decrease the
   limits of the working sets, while decreasing its value tends to
   increase their limits.

   PFRATL has the AUTOGEN, DYNAMIC, and MAJOR attributes.
 

2  PHYSICAL_MEMORY
   (Alpha and Integrity servers) PHYSICAL_MEMORY specifies the
   amount of physical memory available for use. The default setting
   is -1, which equates to all memory in the system. Decreasing this
   parameter allows you to test smaller configurations of memory
   without having to remove memory boards.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   Because of hardware configuration requirements on the AlphaServer
   ES47/ES80/GS1280 systems, VSI does not recommend altering the
   setting of the system parameter PHYSICAL_MEMORY from its default
   setting of -1. Artificially reducing the amount of memory can
   produce unpredictable results on these systems.

   PHYSICAL_MEMORY is an AUTOGEN parameter.

   PHYSICALPAGES is an AUTOGEN parameter.
 

2  PIOPAGES
   PIOPAGES specifies the size of the process I/O segment, which
   holds data structures and buffer pool space for RMS to use
   when it handles I/O that involves process-permanent files. Once
   PIOPAGES is reset in SYSGEN, any new process receives the changed
   value.

   Beginning with OpenVMS Version 7.2, the default value has been
   raised to 575. The setting has been raised to accommodate the
   increased demands for process-permanent memory that result from
   changes made to RMS file-naming parsing in Version 7.2.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   PIOPAGES is an AUTOGEN and DYNAMIC parameter.
 

2  PIXSCAN
   PIXSCAN specifies the number of process index slots scanned each
   second for computable or computable-outswapped processes. These
   processes receive an automatic priority boost for 1 quantum,
   unless the priority of the currently executing process is greater
   than 15. The priority boost is done to avoid potential deadlocks
   on the system.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   PIXSCAN is an AUTOGEN and DYNAMIC parameter.
 

2  POOLCHECK
   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   POOLCHECK is used to investigate frequent and inexplicable
   failures in a system. When POOLCHECK is enabled, pool-checking
   routines execute whenever pool is deallocated or allocated.

   Two loadable forms of SYSTEM_PRIMITIVES.EXE are available at
   boot time. The default image, which contains no pool-checking
   code and no statistics maintenance, is loaded when POOLCHECK
   is set to zero. When POOLCHECK is set to a nonzero value, the
   monitoring version of SYSTEM_PRIMITIVES.EXE, which contains both
   pool-checking code and statistics maintenance, is loaded.

   Setting the SYSTEM_CHECK parameter to 1 has the effect of setting
   POOLCHECK to %X616400FF. For further information about pool
   checking, see the OpenVMS VAX Device Support Manual, (which is
   archived).

   POOLCHECK is a DYNAMIC parameter. However, for a change in its
   value to have any effect, POOLCHECK must be non-0 at boot time
   (to load the monitoring version of SYSTEM_PRIMITIVES.EXE).
 

2  POOLPAGING
   POOLPAGING enables (1)  paging of pageable dynamic pool.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  POWEROFF
   POWEROFF enables or disables software requests to the console
   firmware to remove power from the system. This parameter should
   normally be turned ON (1)  to allow software to make power-off
   requests. However, POWEROFF can be set to OFF (0)  to disable
   software power-off requests.

   If firmware or hardware support for the power-off request is not
   implemented, the shut-down procedure will leave the system halted
   but fully powered.

   POWEROFF is a DYNAMIC parameter.
 

2  PQL_DASTLM
   PQL_DASTLM sets the default limit on the number of pending ASTs
   for a process created by the Create Process ($CREPRC) system
   service or the DCL command RUN (Process).

   PQL_DASTLM has the DYNAMIC and GEN attributes.
 

2  PQL_DBIOLM
   PQL_DBIOLM sets the default buffered I/O count limit for the
   number of outstanding buffered I/O operations permitted to a
   process created by the Create Process ($CREPRC) system service or
   the DCL command RUN (Process).

   PQL_DBIOLM has the DYNAMIC and GEN attributes.
 

2  PQL_DBYTLM
   PQL_DBYTLM sets the default buffered I/O byte count limit for the
   amount of buffered space available to a process created by the
   Create Process ($CREPRC) system service or the DCL command RUN
   (Process).

   PQL_DBYTLM has the DYNAMIC and GEN attributes.
 

2  PQL_DCPULM
   PQL_DCPULM sets the default CPU time limit for a process created
   by the Create Process ($CREPRC) system service or the DCL command
   RUN (Process). PQL_DCPULM specifies the time limit in increments
   of 10 milliseconds.

   The default value of 0 imposes no limit on CPU time usage and is
   typically the correct value for this parameter.

   PQL_DCPULM has the DYNAMIC and GEN attributes.
 

2  PQL_DDIOLM
   PQL_DDIOLM sets the default direct I/O limit for a process
   created by the Create Process ($CREPRC) system service or the
   DCL command RUN (Process).

   PQL_DDIOLM has the DYNAMIC and GEN attributes.
 

2  PQL_DENQLM
   PQL_DENQLM sets the default enqueue limit for a process created
   by the Create Process ($CREPRC) system service or the DCL command
   RUN (Process).

   PQL_DENQLM has the DYNAMIC and GEN attributes.
 

2  PQL_DFILLM
   PQL_DFILLM sets the default open file limit for a process created
   by the Create Process ($CREPRC) system service or the DCL command
   RUN (Process).

   PQL_DFILLM has the DYNAMIC and GEN attributes.
 

2  PQL_DJTQUOTA
   PQL_DJTQUOTA sets the default job table byte count quota for a
   process created by the Create Process ($CREPRC) system service or
   the DCL command RUN (Process). PQL_DJTQUOTA specifies the number
   of bytes of paged pool allocated to the job table. The default
   value is usually adequate, unless a large number of job logical
   names or temporary mailboxes are used.

   PQL_DJTQUOTA is a DYNAMIC parameter.
 

2  PQL_DPGFLQUOTA
   PQL_DPGFLQUOTA sets the default page file quota for a process
   created by the Create Process ($CREPRC) system service or the DCL
   command RUN (Process). VSI recommends that this parameter not be
   smaller than the PQL_DWSEXTENT parameter.

   PQL_DPGFLQUOTA has the DYNAMIC and GEN attributes. On VAX
   systems, PQL_DPGFLQUOTA is also an AUTOGEN parameter.
 

2  PQL_DPRCLM
   PQL_DPRCLM sets the default subprocess limit for a process
   created by the Create Process ($CREPRC) system service or the
   DCL command RUN (Process).

   PQL_DPRCLM has the DYNAMIC and GEN attributes.
 

2  PQL_DTQELM
   PQL_DTQELM sets the default number of timer queue entries for a
   process created by the Create Process ($CREPRC) system service or
   the DCL command RUN (Process).

   PQL_DTQELM has the DYNAMIC and GEN attributes.
 

2  PQL_DWSDEFAULT
   PQL_DWSDEFAULT sets the default working set size for a process
   created by the Create Process ($CREPRC) system service or the DCL
   command RUN (Process).

   PQL_DWSDEFAULT has the AUTOGEN and GEN attributes.
 

2  PQL_DWSEXTENT
   PQL_DWSEXTENT sets the default working set extent for a process
   created by the Create Process ($CREPRC) system service or the DCL
   command RUN (Process).

   PQL_DWSEXTENT has the AUTOGEN, DYNAMIC, and GEN attributes.
 

2  PQL_DWSQUOTA
   PQL_DWSQUOTA sets the default working set quota for a process
   created by the Create Process ($CREPRC) system service or the DCL
   command RUN (Process).

   PQL_DWSQUOTA has the AUTOGEN, DYNAMIC, and GEN attributes.
 

2  PQL_MASTLM
   PQL_MASTLM sets a minimum limit on the number of pending ASTs for
   a process created by the Create Process ($CREPRC) system service
   or the DCL command RUN (Process).

   PQL_MASTLM has the DYNAMIC and GEN attributes.
 

2  PQL_MBIOLM
   PQL_MBIOLM sets the minimum buffered I/O limit for a process
   created by the Create Process ($CREPRC) system service or the DCL
   command RUN (Process).

   PQL_MBIOLM has the DYNAMIC and GEN attributes.
 

2  PQL_MBYTLM
   PQL_MBYTLM sets the minimum buffered I/O byte limit for a process
   created by the Create Process ($CREPRC) system service or the DCL
   command RUN (Process).

   PQL_MBYTLM has the DYNAMIC and GEN attributes.
 

2  PQL_MCPULM
   PQL_MCPULM sets the minimum CPU time limit in increments of
   10 milliseconds for a process created by the Create Process
   ($CREPRC) system service or the DCL command RUN (Process).

   PQL_MCPULM has the DYNAMIC and GEN attributes.
 

2  PQL_MDIOLM
   PQL_MDIOLM sets the minimum direct I/O limit for a process
   created by the Create Process ($CREPRC) system service or the
   DCL command RUN (Process).

   PQL_MDIOLM has the DYNAMIC and GEN attributes.
 

2  PQL_MENQLM
   PQL_MENQLM sets the minimum limit on the number of locks that can
   be queued at one time by a process created by the Create Process
   ($CREPRC) system service or the DCL command RUN (Process).

   PQL_MENQLM has the DYNAMIC and GEN attributes.
 

2  PQL_MFILLM
   PQL_MFILLM sets the minimum open file limit for a process created
   by the Create Process ($CREPRC) system service or the DCL command
   RUN (Process).

   PQL_MFILLM has the DYNAMIC and GEN attributes.
 

2  PQL_MJTQUOTA
   PQL_MJTQUOTA sets the minimum job table byte count quota for a
   process created by the Create Process ($CREPRC) system service or
   the DCL command RUN (Process).

   PQL_MJTQUOTA is a DYNAMIC parameter.
 

2  PQL_MPGFLQUOTA
   On VAX systems, PQL_MPGFLQUOTA sets the minimum page file quota
   for a process created by the Create Process ($CREPRC) system
   service or the DCL command RUN (Process). VSI recommends that this
   parameter be no smaller than PQL_MWSEXTENT.

   On Alpha and Integrity servers, PQL_MPGFLQUOTA sets the minimum
   pagelet file quota for a process created by the Create Process
   ($CREPRC) system service or the DCL command RUN (Process).

   PQL_MPQFLQUOTA has the DYNAMIC and GEN attributes. On VAX
   systems, PQL_MPQFLQUOTA is also an AUTOGEN parameter.
 

2  PQL_MPRCLM
   PQL_MPRCLM sets the minimum subprocess limit for a process
   created by the Create Process ($CREPRC) system service or the
   DCL command RUN (Process).

   PQL_MPRCLM has the DYNAMIC and GEN attributes.
 

2  PQL_MTQELM
   PQL_MTQELM sets the minimum number of timer queue entries for a
   process created by the Create Process ($CREPRC) system service or
   the DCL command RUN (Process).

   PQL_MTQELM has the DYNAMIC and GEN attributes.
 

2  PQL_MWSDEFAULT
   PQL_MWSDEFAULT sets the minimum default working set size for a
   process created by the Create Process ($CREPRC) system service or
   the DCL command RUN (Process).

   This value overrides a smaller quantity that is set for a user in
   AUTHORIZE.

   PQL_MWSDEFAULT has the AUTOGEN and GEN attributes.
 

2  PQL_MWSEXTENT
   PQL_MWSEXTENT sets the minimum working set extent for a process
   created by the Create Process ($CREPRC) system service or the DCL
   command RUN (Process).

   This value overrides a smaller quantity set for a user in
   AUTHORIZE.

   PQL_MWSEXTENT has the AUTOGEN, DYNAMIC, and GEN attributes.
 

2  PQL_MWSQUOTA
   PQL_MWSQUOTA sets the minimum working set quota for a process
   created by the Create Process ($CREPRC) system service or the DCL
   command RUN (Process).

   This value overrides a smaller quantity set for a user in
   AUTHORIZE.

   PQL_MWSQUOTA has the AUTOGEN, DYNAMIC, and GEN attributes.
 

2  PRCPOLINTERVAL
   PRCPOLINTERVAL specifies, in seconds, the polling interval used
   to look for Systems Communications Services (SCS) applications,
   such as the connection manager and mass storage control protocol
   disks, on other nodes. All discovered nodes are polled during
   each interval.

   This parameter trades polling overhead against quick recognition
   of new systems or servers as they appear.

   PRCPOLINTERVAL is a DYNAMIC parameter. On Alpha and Integrity
   servers, PRCPOLINTERVAL is also an AUTOGEN parameter.
 

2  PRIORITY_OFFSET
   PRIORITY_OFFSET specifies the difference in priority required
   by the scheduler for one process to preempt the current process.
   A value of 2, for example, means that if the current process
   is executing at priority 1, a computable process at priority 2
   or 3 is not allowed to preempt the current process. However, a
   priority 4 or higher process can preempt the current process.
   This mechanism affects only normal priority (0-15) processes. The
   default value is 0.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  PROCSECTCNT
   PROCSECTCNT sets the number of section descriptors that a process
   can contain. Each section descriptor increases the fixed portion
   of the process header by 32 bytes.

   Set a value greater than the maximum number of image sections
   in any section to be run, as indicated by the linkage memory
   allocation map for the image.

   PROCSECTCNT has the AUTOGEN and GEN attributes.
 

2  PU_OPTIONS
   PU_OPTIONS is reserved for VSI use only.
 

2  QDSKINTERVAL
   QDSKINTERVAL establishes, in seconds, the disk quorum polling
   interval. The default value is 3.
 

2  QDSKVOTES
   QDSKVOTES specifies the number of votes contributed by a quorum
   disk in a cluster.
 

2  QUANTUM
   QUANTUM defines the following:

   o  Processor time: maximum amount of processor time a process
      can receive before control passes to another process of equal
      priority that is ready to compute

   o  Balance set residency: minimum amount of service a compute-
      state process must receive before being swapped out to
      secondary storage

   QUANTUM has the DYNAMIC and MAJOR attributes. On Alpha and
   Integrity servers, QUANTUM also has the AUTOGEN attribute.
 

2  RAD_SUPPORT
   RAD_SUPPORT enables RAD-aware code to be executed
   on systems that support Resource Affinity Domains (RADs);
   for example, AlphaServer GS160 systems and Integrity 
   cell-based servers or BL8x0c i2 servers. A RAD is a set of
   hardware components (CPUs and memory) with common access
   characteristics.

   Bits are defined in the RAD_SUPPORT parameter as follows:

   RAD_SUPPORT (default is 207 for Alpha and 10944667 
   for Integrity servers)
   ___________________________________________________

    3   2 2   2 2         1 1
    1   8 7   4 3         6 5         8 7         0
   +-----+-----+-----------+-----------+-----------+
   |00|00| skip|ss|gg|ww|pp|00|00|00|00|0p|df|cr|ae|
   +-----+-----+-----------+-----------+-----------+

   Bit 0 (e): Enable    - Enables RAD support

   Bit 1 (a): Affinity  - Enables Soft RAD Affinity (SRA) scheduling
                          Also enables the interpretation of the skip
                          bits, 24-27.

   Bit 2 (r): Replicate - Enables system-space code replication

   Bit 3 (c): Copy      - Enables copy on soft fault

   Bit 4 (f): Fault     - Enables special page fault allocation
                          Also enables the interpretation of the
                          allocation bits, 16-23.

   Bit 5 (d): Debug     - Reserved to VSI

   Bit 6 (p): Pool      - Enables per-RAD non-paged pool

   Bits 7-15:           - Reserved to VSI

   Bits 16-23:          - If bit 4 is set, bits 16-23 are interpreted
                          as follows:

   Bits 16,17 (pp): Process = Pagefault on process (non global)
                              pages
   Bits 18,19 (ww): Swapper = Swapper's allocation of pages for
                              processes
   Bits 20,21 (gg): Global  = Pagefault on global pages
   Bits 22,23 (ss): System  = Pagefault on system space pages

   Encodings for pp, ww, gg, ss:
   Current  (0) - allocate PFNs from the current CPU's RAD
   Random   (1) - allocate PFNs using the "random" algorithm
   Base     (2) - allocate PFNs from the operating system's "base"
                  RAD
   Home     (3) - allocate PFNs from the current process's home RAD

   If bits 16-23 are 0, the defaults for pp, ww, gg, ss are interpreted
   as follows:

       Process = home RAD
       Swapper = current RAD (also sets home RAD for process)
       Global  = random RAD
       System  = base RAD

   Bits 24-27:   - If bit 1 is set, bits 24-27 are interpreted
                   as a skip count value (power of 2). Example: If
                   bits 24-27 contain a 3, the skip count is 8.
                   If bits 24-27 contain a 5, the skip count is 32.
                   If bits 24-27 are 0, the default of 16 is used
                   as the skip count.

   Bits 28-31:   - Reserved to VSI

   For more information about using OpenVMS RAD features, see the
   OpenVMS Alpha Galaxy and Partitioning Guide or VSI OpenVMS 
   Version 8.4 New Features and Documentation Overview.

   RAD_SUPPORT has the GEN attribute.

   REALTIME_SPTS has the DYNAMIC, GEN, and MAJOR attributes.
 

2  RECNXINTERVAL
   RECNXINTERVAL establishes the polling interval, in seconds,
   during which to attempt reconnection to a remote system.

   RECNXINTERVAL is a DYNAMIC parameter. On Alpha and Integrity
   servers, RECNXINTERVAL is also an AUTOGEN parameter.
 

2  RESALLOC
   RESALLOC controls whether resource allocation checking is
   performed. The default value of 0 disables resource allocation
   checking.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  RESHASHTBL
   RESHASHTBL defines the number of entries in the lock management
   resource name hash table. Each entry requires 4 bytes. A typical
   tuning goal is to have the RESHASHTBL parameter about four times
   larger than the total number of resources in use on the system.
   Managers of systems with memory constraints or systems that are
   not critically dependent on locking speed could set the table to
   a smaller size.

   RESHASHTBL has the AUTOGEN, FEEDBACK, and MAJOR attributes.
 

2  RJOBLIM
   RJOBLIM defines the maximum number of remote terminals allowed in
   the system at any one time.

   RJOBLIM is a DYNAMIC parameter.
 

2  RMS_CONPOLICY
   RMS_CONPOLICY specifies the policy to be used for dealing with
   high-contention write-shared files. This dynamic parameter can
   be used to ensure fairness between lock conversions and new lock
   requests.

   Possible values are the following:

   Value          Explanation

   NEVER          (Default) Never use the higher overhead option
                  to improve fairness for any write-shared files
                  accessed on the system; minimal overhead.
   SOMETIMES      Use this option for fairer bucket access (but
                  higher overhead) to any write-shared files with
                  global buffers enabled that are accessed on the
                  system.
   ALWAYS         Use this option for fairer bucket access (but
                  higher overhead) to all write-shared files
                  accessed on the system.

   You can set this system parameter with the DCL command SET RMS_
   DEFAULT/SYSTEM/CONTENTION_POLICY=value and display the parameter
   with the DCL command SHOW RMS_DEFAULT.

   RMS_CONPOLICY is a DYNAMIC parameter.
 

2  RMSD*
   RMSD1, RMSD2, RMSD3, RMSD4, RMSD5, RMSD6, and RMSD7 are special
   parameters reserved for VSI use.

   RMSD* parameters are DYNAMIC.
 

2  RMS_DFLRL
   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   RMS_DFLRL is a DYNAMIC parameter.
 

2  RMS_DFMBC
   RMS_DFMBC specifies a default multiblock count only for record
   I/O operations, where count is the number of blocks to be
   allocated for each I/O buffer.

   You can set this system parameter with the DCL command SET RMS_
   DEFAULT/SYSTEM and display the parameter with the SHOW RMS_
   DEFAULT command.

   RMS_DFMBC is an AUTOGEN and DYNAMIC parameter.
 

2  RMS_DFMBFIDX
   RMS_DFMBFIDX establishes the default RMS multibuffer count for
   indexed sequential disk operations. This value defines the number
   of I/O buffers that RMS allocates for each indexed file. For
   sequential access, a larger number that allows some of the index
   buckets to remain in memory can improve performance.

   You can set this system parameter with the DCL command
   SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
   DEFAULT.

   RMS_DFMBFIDX is an AUTOGEN and DYNAMIC parameter.
 

2  RMS_DFMBFREL
   RMS_DFMBFREL establishes the default RMS multibuffer count for
   relative disk operations. This value defines the number of I/O
   buffers that RMS allocates for each relative file.

   You can set this system parameter with the DCL command
   SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
   DEFAULT.

   RMS_DFMBFREL is an AUTOGEN and DYNAMIC parameter.
 

2  RMS_DFMBFSDK
   RMS_DFMBFSDK establishes the default RMS multibuffer count for
   sequential disk operations. This value defines the number of I/O
   buffers that RMS allocates for sequential disk files.

   The default value is usually adequate. However, if read-ahead
   or write-behind operations are used, a larger number improves
   performance.

   You can set this system parameter with the DCL command
   SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
   DEFAULT.

   RMS_DFMBFSDK is an AUTOGEN and DYNAMIC parameter.
 

2  RMS_DFMBFSMT
   RMS_DFMBFSMT establishes the default RMS multibuffer count for
   magnetic tape operations. This value defines the number of I/O
   buffers that RMS allocates for magnetic tape files.

   You can set this system parameter with the DCL command
   SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
   DEFAULT.

   RMS_DFMBFSMT is an AUTOGEN and DYNAMIC parameter.
 

2  RMS_DFMBFSUR
   RMS_DFMBFSUR establishes the default multibuffer count for unit
   record devices.

   You can set this system parameter with the DCL command
   SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
   DEFAULT.

   RMS_DFMBFSUR is an AUTOGEN and DYNAMIC parameter.
 

2  RMS_DFNBC
   RMS_DFNBC specifies a default block count for network access to
   remote, sequential, indexed sequential, and relative files.

   The network block count value represents the number of blocks
   that RMS is prepared to allocate for the I/O buffers used to
   transmit and receive data. The buffer size used for remote file
   access, however, is the result of a negotiation between RMS and
   the remote file access listener (FAL). The buffer size chosen is
   the smaller of the two sizes presented.

   Thus, RMS_DFNBC places an upper limit on the network buffer size
   that is used. It also places an upper limit on the largest record
   that can be transferred to or from a remote file. In other words,
   the largest record that can be transferred must be less than or
   equal to RMS_DFNBC multiplied by 512 bytes.

   You can set this system parameter with the DCL command
   SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
   DEFAULT.

   RMS_DFNBC is an AUTOGEN and DYNAMIC parameter.
 

2  RMS_EXTEND_SIZE
   RMS_EXTEND_SIZE specifies the number of blocks by which files
   are extended as they are written. This number should be chosen to
   balance the amount of extra disk space wasted at the ends of each
   file against the performance improvement provided by making large
   extents infrequently.

   When small disk quotas are used, specify a small number such as
   the disk cluster size to prevent the user's disk quota from being
   consumed. If the value of 0 is used, RMS allocates large extents
   and truncates the file back to its actual usage when it closes.

   You can set this system parameter with the DCL command
   SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
   DEFAULT.

   RMS_EXTEND_SIZE is a DYNAMIC parameter.
 

2  RMS_FILEPROT
   RMS_FILEPROT determines the default file protection for system
   processes such as those that create the error log, operator log,
   and job controller. It also determines default file protection
   for processes created by the job controller (all interactive and
   batch processes).

   Because a process always inherits its default file protection
   from its creator process, RMS_FILEPROT determines default file
   protection only for users who do not execute the DCL command SET
   PROTECTION/DEFAULT in their login command procedures or during
   interactive sessions.

   The protection is expressed as a mask. (See the discussion of
   the $CRMPSC system service in the VSI OpenVMS System Services
   Reference Manual for more information about specifying protection
   masks.) By default, the mask is 64000 (decimal) or FA00
   (hexadecimal), which represents the following protection:

   (S:RWED,O:RWED,G:RE,W:)
 

2  RMS_HEURISTIC
   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   RMS_HEURISTIC is a DYNAMIC parameter.
 

2  RMS_PATH_TMO
   The RMS path cache in each process holds entries that translate
   DVI+DID+name to new DVI+DID. These are used to greatly speed
   up directory path walks. Cache entries representing ordinary
   directory lookups are invalidated through the volume directory
   sequence number mechanism (UDB$L_DIRSEQ), which is clocked
   on every volume dismount and each time a directory is deleted
   or renamed. However, there is no convenient mechanism for
   invalidating a cache entry that represents a symlink, whose
   interpretation is affected by logical names or modification of
   the symlink. The only way to eliminate stale cache entries is
   with a timeout. This parameter is the system-wide cache timeout.
   Special values:

         1 = don't keep cache entries
        -1 = keep cache entries forever
RMS_PATH_TMO is a DYNAMIC parameter.
 

2  RMS_PROLOGUE
   RMS_PROLOGUE specifies the default prologue RMS uses to create
   indexed files. The default value 0 specifies that RMS should
   determine the prologue based on characteristics of the file. A
   value of 2 specifies Prologue 2 or Prologue 1, and 3 specifies
   Prologue 3. The RMS prologues are described in the OpenVMS Record
   Management Services Reference Manual.

   RMS_PROLOGUE is a DYNAMIC parameter.
 

2  RMS_SEQFILE_WBH
   (Alpha and Integrity servers) RMS_SEQFILE_WBH can enable the
   RMS writebehind feature as a system default for any unshared
   sequential disk file if the file is opened for image I/O with
   write access specified. The possible settings are the following:

   Setting        Description

   0 (default)    Do not enable writebehind feature. Preserve prior
                  behavior of using writebehind only if the user
                  requests it by setting RAB$V_WBH in RAB$L_ROP.

   1              Enable writebehind feature as system default,
                  including the allocation of at least two local
                  buffers.

   RMS_SEQFILE_WBH is a DYNAMIC parameter.
 

2  S0_PAGING
   S0_PAGING controls paging of system code:

   o  Setting bit 0 disables paging of all Exec code and data.

   o  Setting bit 1 disables paging of all RMS code and data.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  S2_SIZE
   (Alpha and Integrity servers) S2_SIZE is the number of megabytes
   to reserve for S2 space. This value does not include the size
   required for extended file cache (XFC).
 

2  SAVEDUMP
   If the dump file is saved in the page file, SAVEDUMP specifies
   whether the page file is saved until the dump file is analyzed.
   The default value 0 specifies that the page file should not be
   retained. A value of 1 specifies that the dump written to the
   page file should be retained until either copied or released
   using the SDA utility.
 

2  SCHED_FLAGS
   Special DYNAMIC parameter reserved for VSI use.
 

2  SCH_HARD_OFFLD
   The scheduler hard off-load parameter is a CPU bitmask parameter.
   The bits correspond to CPU IDs. For any bit set, the OpenVMS
   scheduler does not schedule processes on this CPU unless the
   process has hard affinity set for the CPU. In addition, a process
   with the PRIMARY capability requirement will ignore the bit
   corresponding to the primary CPU.

   SCH_HARD_OFFLD is a DYNAMIC parameter.
 

2  SCH_SOFT_OFFLD
   The scheduler soft off-load parameter is a CPU bitmask parameter.
   The bits correspond to CPU IDs. For any bit set, the OpenVMS
   scheduler tries to avoid scheduling processes on this CPU.
   However, if no other idle CPUs exist, processes are still
   scheduled on this CPU.

   SCH_SOFT_OFFLD is a DYNAMIC parameter.
 

2  SCSBUFFCNT
   On VAX systems, SCSBUFFCNT is the number of buffer descriptors
   configured for all systems communication architecture (SCA). If
   an SCA device is not configured on your system, this parameter is
   ignored. Generally speaking, each data transfer needs a buffer
   descriptor and thus the number of buffer descriptors can be
   a limit on the number of possible simultaneous I/Os. Various
   performance monitors report when a system is out of buffer
   descriptors for a given workload which is an indication that
   a larger value for SCSBUFFCNT is worth considering. Note that
   AUTOGEN provides feedback for this parameter on VAX systems only.

   On Alpha and Integrity servers, the system communication services
   (SCS) buffers are allocated as needed, and SCSBUFFCNT is reserved
   for VSI use only.

   SCSBUFFCNT has the AUTOGEN, FEEDBACK, and GEN attributes.
 

2  SCSFLOWCUSH
   Specifies the lower limit for receive buffers at which point
   system communication services (SCS) starts to notify the remote
   SCS of new receive buffers. For each connection, SCS tracks the
   number of receive buffers available. SCS communicates this number
   to the SCS at the remote end of the connection. However, SCS does
   not need to do this for each new receive buffer added. Instead,
   SCS notifies the remote SCS of new receive buffers if the number
   of receive buffers falls as low as the SCSFLOWCUSH value.

   The default value is adequate on most systems. If a systems
   communication architecture (SCA) port is not configured on your
   system, this parameter is ignored.

   SCSFLOWCUSH is a DYNAMIC parameter.
 

2  SCSI_ERROR_POLL
   If an error occurs while a particular initiator is accessing
   a SCSI device, that error is latched for all other initiators
   and is not unlatched and reported to the other initiators until
   the next time they access the device. Therefore, if the other
   initiators do not access the device in a timely manner, the
   reporting of the error can be greatly delayed, which can cause
   confusion.

   The purpose of SCSI_ERROR_POLL is to cause OpenVMS to send a
   SCSI Test Unit Ready command every hour to each SCSI disk, in
   an attempt to force latched errors to become unlatched and to
   be reported immediately. SCSI_ERROR_POLL has a default value of
   1. It can, however, be set to 0 by the user in order to stop the
   error polling activity.

   The parameter affects SCSI disks connected by Fibre Channel as
   well as parallel SCSI. If the disk has multiple paths, then the
   error polling is performed on all non-served paths to the disk.
   Tapes and other non-disk devices are not subject to this error
   polling, regardless of the parameter setting.

   SCSI_ERROR_POLL is a DYNAMIC parameter.

   SCSI_NOAUTO is a DYNAMIC parameter.
 

2  SCSICLUSTER_P[1-4]
   (Alpha only) SCSICLUSTER_P[1-4] parameters allow non-HP
   peripherals (CPU-lookalikes) in SCSI clusters.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  SCSMAXDG
   This parameter is reserved for VSI use only.

   SCSMAXDG has the GEN attribute.
 

2  SCSMAXMSG
   This parameter is reserved for VSI use only.

   SCSMAXMSG has the GEN attribute.
 

2  SCSNODE
   SCSNODE specifies the name of the computer. This parameter is not
   dynamic.

   Specify SCSNODE as a string of up to six characters. Enclose the
   string in quotation marks.

                                  NOTE

      The maximum size of six characters is strictly enforced.
      SYSBOOT truncates the value of SCSNODE if the size of the
      system parameter is set to more than six characters.

   If the computer is in an OpenVMS Cluster, specify a value that is
   unique within the cluster. Do not specify the null string.

   If the computer is running DECnet for OpenVMS, the value must be
   the same as the DECnet node name.

   SCSNODE has the AUTOGEN and GEN attributes.
 

2  SCSRESPCNT
   SCSRESPCNT is the total number of response descriptor table
   entries (RDTEs) configured for use by all system applications.

   If SCA or DSA ports are not configured on your system, the system
   ignores SCSRESPCNT.

   SCSRESPCNT has the AUTOGEN, FEEDBACK, and GEN attributes.
 

2  SCSSYSTEMID
   Specifies a number that identifies the computer. This parameter
   is not dynamic. SCSSYSTEMID is the low-order 32 bits of the 48-
   bit system identification number.

   If the computer is in an OpenVMS Cluster, specify a value that is
   unique within the cluster. Do not use zero as the value.

   If the computer is running DECnet for OpenVMS, calculate the
   value from the DECnet address using the following formula:

   SCSSYSTEMID = ((DECnet area number) * 1024) + (DECnet node number)

   Example: If the DECnet address is 2.211, calculate the value as
   follows:

   SCSSYSTEMID = (2 * 1024) + 211 = 2259

   SCSSYSTEMID has the GEN attribute.
 

2  SCSSYSTEMIDH
   Specifies the high-order 16 bits of the 48-bit system
   identification number. This parameter must be set to 0. It is
   reserved by VSI for future use.

   SCSSYSTEMIDH has the GEN attribute.
 

2  SECURITY_POLICY
   SECURITY_POLICY allows a system to run in a C2 or B1
   configuration and to subset out particular pieces of
   functionality-to exclude functionality that is outside the
   evaluated configuration or to preserve compatibility with
   previous versions of the operating system. See the VSI OpenVMS
   Guide to System Security for further information about the C2 and
   B1 evaluated configurations.

   The following bits are defined:

   Bit   Description

   0     Obsolete.

   1     Allows multiple user names to connect to DECW$SERVER.

   2     Allows unevaluated DECwindows transports (such as TCP/IP).

   3     Allows $SIGPRC and $PRCTERM to span job trees.

   4     Allows security profile changes to protected objects on
         a local node when the object server is absent and cannot
         update the cluster database VMS$OBJECTS.DAT.

   5     Allows creation of protected objects on a local node when
         the object server is absent and cannot update the cluster
         database VMS$OBJECTS.DAT.

   6     Allows SPAWN or LIB$SPAWN commands in CAPTIVE accounts.

   7     Reserved to VSI.

   8     Reserved to VSI.

   9     Disables password synchronizations among ACME agents on
         a systemwide pasis. This is functionally equivalent to
         the SYS$SINGLE_SIGNON logical name bit mask value 4 for
         LOGINOUT.

   10    Allows privileged applications to successfully authenticate
         a user whose principal name maps to a SYSUAF record that is
         either expired or whose modal restrictions would otherwise
         prevent the account from being used.

         A SYSUAF record that is disabled or password-expired (in
         the case of traditional OpenVMS authentication) cannot be
         bypassed in this manner.

         An application with SECURITY privilege specifies the
         SYS$ACM ACME$M_NOAUTHORIZE function modifier to override
         authorization checks.

   11    Allows any record in the SYSUAF file to be mapped using
         external authentication.

   12    Allows intrusions on a clusterwide or local basis. (If the
         bit is cleared, intrusions are clusterwide.)

   13    Reserved to VSI.

   14    Allows the internal name and backlink of files and
         directories to be read if the user has either execute or
         read access to the file or directory. If this bit is clear,
         read access is required.

         Setting this bit allows the full POSIX pathname of a file
         or directory to be displayed when some of the directories
         in the path are execute-only to the user. This feature is
         required in the following environments:

         o  POSIX pathnames are in use.

         o  The BASH shell or other GNV components are in use.

         o  Applications are using the realpath(),  getcwd(),
            getpwnam(),  and related C runtime library functions.

   The default value of 7 preserves compatibility with existing
   DECwindows Motif behavior. A value of 0 disables all unevaluated
   configurations.
 

2  SETTIME
   SETTIME enables (1)  or disables (0) solicitation of the time of
   day each time the system is booted. This parameter should usually
   be off (0), so that the system sets the time of day at boot time
   to the value of the processor time-of-day register. You can reset
   the time after the system is up with the DCL command SET TIME
   (see the VSI OpenVMS DCL Dictionary).
 

2  SHADOW_D1-D5
   Special DYNAMIC parameters reserved for VSI use.
 

2  SHADOW_ENABLE
   Special parameter reserved for VSI use.
 

2  SHADOWING
   SHADOWING loads the host-based volume shadowing driver. See VSI
   Volume Shadowing for OpenVMS for more information about setting
   system parameters for volume shadowing.

   Specify one of the following values:

   Value  Description

   0      No shadowing is enabled; SHDRIVER is not loaded. This is
          the default value.

   2      Host-based volume shadowing enabled; SHDRIVER is loaded.
          Host-based volume shadowing provides shadowing of all
          disks located on a standalone system or an OpenVMS Cluster
          system.
 

2  SHADOW_HBMM_RTC
   (Alpha and Integrity servers) SHADOW_HBMM_RTC specifies, in
   seconds, how frequently each shadow set on this system has its
   modified block count compared with the reset threshold. If the
   modified block count exceeds the reset threshold, the bitmap for
   that shadow set is zeroed. This comparison is performed for all
   shadow sets mounted on the system that have HBMM bitmaps.

   The reset threshold is specified by the RESET_THRESHOLD keyword
   in the /POLICY qualifier of the SET SHADOW command.

   When the comparison is made, the modified block count might
   exceed the reset threshold by a small increment or by a much
   larger amount. The difference depends on the write activity to
   the volume and on the setting of this parameter.

   SHADOW_HBMM_RTC is a DYNAMIC parameter.
 

2  SHADOW_MAX_COPY
   The value of SHADOW_MAX_COPY controls how many parallel copy
   threads are allowed on a given node.

   Carefully consider the needs of each shadowed node when you
   set this parameter. Too high a value for SHADOW_MAX_COPY can
   affect performance by allowing too many copy threads to operate
   in parallel. Too low a value unnecessarily restricts the number
   of threads your system can effectively handle.

   See VSI Volume Shadowing for OpenVMS for more information about
   setting system parameters for volume shadowing.

   SHADOW_MAX_COPY has the AUTOGEN and DYNAMIC attributes.
 

2  SHADOW_MAX_UNIT
   SHADOW_MAX_UNIT specifies the maximum number of shadow sets that
   can exist on a system. The setting must be equal to or greater
   than the number of shadow sets you plan to have on a system.
   Dismounted shadow sets, unused shadow sets, and shadow sets with
   no write bitmaps allocated to them are included in the total.

                                  NOTE

      Review this default carefully. The setting must be equal to
      or greater than the number of shadow sets you plan to have
      on a system. If you attempt to mount more shadow sets than
      the number specified by SHADOW_MAX_UNIT, the MOUNT command
      will fail. Dismounted shadow sets, unused shadow sets, and
      shadow sets with no write bitmaps allocated to them are
      included in the count for SHADOW_MAX_UNIT.

   On Alpha and Integrity servers, the default value for this system
   parameter is 500, which consumes 24 KB of main memory.

   If you do not plan to use Volume Shadowing for OpenVMS, you can
   change the setting to its minimum of 10 (which consumes 480 bytes
   of main memory). Setting the default to its minimum frees up 23.5
   KB of main memory on an OpenVMS Alpha or Integrity servers and
   4.5 KB of main memory on a VAX system. (The maximum value of this
   parameter is 10,000.)

   This system parameter is not dynamic; that is, a reboot is
   required when you change the setting.
 

2  SHADOW_MBR_TMO
   SHADOW_MBR_TMO controls the amount of time the system tries to
   fail over physical members of a shadow set before removing them
   from the set. The SHADOW_MBR_TMO parameter replaces the temporary
   VMSD3 parameter used in prior releases.

   The SHADOW_MBR_TMO parameter is valid for use only with Phase II
   of Volume Shadowing for OpenVMS. You cannot set this parameter
   for use with Phase I, which is obsolete.

   Use the SHADOW_MBR_TMO parameter (a word) to specify the number
   of seconds, in decimal from 1 to 65,535, during which recovery
   of a repairable shadow set is attempted. If you do not specify
   a value or if you specify 0, the default delay of 120 seconds is
   used.

   Because SHADOW_MBR_TMO is a dynamic parameter, you should use the
   SYSGEN command WRITE CURRENT to permanently change its value.

   SHADOW_MBR_TMO is a DYNAMIC parameter.
 

2  SHADOW_PSM_RDLY
   When a copy or merge operation is needed on a shadow set that is
   mounted on more than one system, the shadowing driver attempts
   to perform the operation on a system that has a local connection
   to all the shadow set members. Shadowing implements the copy or
   merge operation by adding a time delay based on the number of
   shadow set members that are MSCP-served to the system. No delay
   is added for local members; a system with all locally accessible
   shadow set members usually performs the copy or merge before a
   system on which one or more members is served (and therefore is
   delayed) does.

   SHADOW_PSM_RDLY allows the system manager to adjust the delay
   that shadowing adds. By default, the delay is 30 seconds for each
   MSCP-served shadow set member. The valid range for the specified
   delay is 0 through 65,535 seconds.

   When a shadow set is mounted on a system, the value of SHADOW_
   PSM_RDLY is used as the default shadow set member recovery delay
   for that shadow set. To modify SHADOW_PSM_RDLY for an existing
   shadow set, see the SET SHADOW/ /RECOVERY_OPTIONS=DELAY_PER_
   SERVED_MEMBER=n command in VSI Volume Shadowing for OpenVMS.
 

2  SHADOW_REC_DLY
   (Alpha and Integrity servers)

   The value of the SHADOW_REC_DLY parameter specifies the length
   of time a system waits before it attempts to manage recovery
   operations on shadow sets that are mounted on the system.
   A shadow set is said to need recovery when a merge or copy
   operation is required on that shadow set.

   SHADOW_REC_DLY can be used to better predict which systems in
   an OpenVMS Cluster performs recovery operations. This is done
   by setting lower values of SHADOW_REC_DLY on systems that are
   preferred to handle recovery operations and higher values of
   SHADOW_REC_DLY on systems that are least preferred to handle
   recovery operations.

   The range of SHADOW_REC_DLY is 20 to 65535 seconds. The default
   value is 20 seconds.

   For more information about controlling which systems perform the
   merge or copy operations, see VSI Volume Shadowing for OpenVMS.

   SHADOW_REC_DLY is a DYNAMIC parameter.
 

2  SHADOW_SITE_ID
   (Alpha and Integrity servers) This parameter allows a system
   manager to define a site value, which Volume Shadowing uses to
   determine the best device to perform reads, thereby improving
   performance.

   The system manager can now define the site value to be used
   for all shadow sets mounted on a system. This parameter is an
   arbitrary numeric value coordinated by the system manager of
   disaster tolerant clusters. Reads from devices that have site
   values matching the shadow set's site value are preferred over
   reads from devices with different site values. For detailed
   information, see the description of the $SET DEVICE/SITE in the
   VSI OpenVMS DCL Dictionary and VSI Volume Shadowing for OpenVMS.

   SHADOW_SITE_ID is a DYNAMIC parameter.
 

2  SHADOW_SYS_DISK
   A SHADOW_SYS_DISK parameter value of 1 enables shadowing of the
   system disk. A value of 0 disables shadowing of the system disk.
   The default value is 0.

   Also specify a system disk shadow set virtual unit number with
   the SHADOW_SYS_UNIT system parameter, unless the desired system
   disk unit number is DSA0.

   A value of 4096 enables CI-based minimerge. To enable minimerge
   on a system disk, however, you must enable DOSD by setting the
   DUMPSTYLE parameter to dump off system disk, as described in the
   VSI OpenVMS System Manager's Manual. You can then add the value
   4096 to your existing SHADOW_SYS_DISK value. For example, if you
   have SHADOW_SYS_DISK set to a value of 1, change it to 4097 to
   enable minimerge.
 

2  SHADOW_SYS_TMO
   The SHADOW_SYS_TMO parameter has the following two distinct uses:

   o  At system boot time, when this is the first node in the
      cluster to boot and to create this specific shadow set. If the
      proposed shadow set is not currently mounted in the cluster,
      use this parameter to extend the time a booting system waits
      for all former members of the shadowed system disk to become
      available.

   o  Once the system successfully mounts the virtual unit and
      begins normal operations. In this usage, the SHADOW_SYS_
      TMO parameter controls the time the operating system waits
      for errant members of a system disk. (Use the SHADOW_MBR_TMO
      parameter to control the time the operating system waits for
      the errant members of an application disk.)

   This parameter applies only to members of the system disk shadow
   set. All nodes using a particular system disk shadow set should
   have their SHADOW_SYS_TMO parameter set to the same value once
   normal operations begin.

   The default value is 120 seconds. Change this parameter to a
   higher value if you want the system to wait more than the 120-
   second default for all members to join the shadow set. You can
   set the parameter value to 120 through 65,535 seconds.
 

2  SHADOW_SYS_UNIT
   Use this parameter for Phase II shadowing only. The SHADOW_SYS_
   UNIT parameter is an integer value that contains the virtual unit
   number of the system disk. The default value is 0. The maximum
   value allowed is 9999. This parameter is effective only when the
   SHADOW_SYS_DISK parameter has a value of 1. This parameter should
   be set to the same value on all nodes booting off a particular
   system disk shadow set. See VSI Volume Shadowing for OpenVMS
   for more information about setting system parameters for volume
   shadowing.
 

2  SHADOW_SYS_WAIT
   The SHADOW_SYS_WAIT parameter extends the time a booting system
   waits for all current members of a mounted shadowed system disk
   to become available to this node. The shadow set must already be
   mounted by at least one other cluster node for this parameter to
   take effect.

   The default value is 480 seconds. Change this parameter to a
   higher value if you want the system to wait more than the 480-
   second default for all members to join the shadow set. You can
   set the parameter value to 1 through 65,535 seconds.
 

2  SMCI_FLAGS
   (Alpha Galaxy platforms only) The SMCI_FLAGS parameter controls
   operational aspects of SYS$PBDRIVER, the Galaxy Shared Memory
   Cluster Interconnect (SMCI).

   Bits in the bit mask are the following:

   Bit  Mask                        Description

   0    0     0 =  Do not create local communications channels
                   (SYSGEN default). Local SCS communications are
                   primarily used in test situations and are not
                   needed for normal operations. Not creating local
                   communications saves resources and overhead.

              1 =  Create local communications channels.

   1    2     0 =  Load SYS$PBDRIVER if booting into both a Galaxy
                   and a Cluster (SYSGEN Default).

              1 =  Load SYS$PBDRIVER if booting into a Galaxy.

   2    4     0 =  Minimal console output (SYSGEN default).

              1 =  Full console output; SYS$PBDRIVER displays
                   console messages when it creates and tears down
                   communications channels.

   SMCI_FLAGS has the DYNAMIC attribute.
 

2  SMCI_PORTS
   On systems running OpenVMS Galaxy software, the Shared Memory
   Cluster Interconnect (SMCI) system parameter SMCI_PORTS controls
   initial loading of SYS$PBDRIVER. This parameter is a bit mask;
   bits 0 through 25 each represent a controller letter. If bit 0
   is set, which is the default setting, PBAx is loaded (where x
   represents the Galaxy Partition ID). If bit 1 is set, PBBx is
   loaded, and so on up to bit 25, which causes PBZx to be loaded.
   For OpenVMS Alpha Version 7.2 and later, VSI recommends leaving
   this parameter at the default value of 1.

   Loading additional ports allows multiple paths between Galaxy
   instances. In the initial release of the Galaxy software, having
   multiple communications channels is not an advantage because
   SYS$PBDRIVER does not support fast path. A future release
   of OpenVMS will provide Fast Path support for SYS$PBDRIVER,
   when multiple CPUs improve throughput by providing multiple
   communications channels between instances.
 

2  SMP_CPU_BITMAP
   This parameter indicates that the corresponding CPU is a bitmap
   representing up to 1024 CPUs. Each bit set in this bitmap
   indicates that the corresponding CPU automatically attempts
   to join the active set in an OpenVMS symmetric multiprocessing
   environment when the instance is booted. A cleared bit indicates
   that the corresponding CPU is ignored only at boot time; if it is
   otherwise viable, the CPU can be started at a later time.

   SMP_CPU_BITMAP defaults to all bits set. (CPU 0 through CPU 1023
   are enabled for multiprocessing.) Note that the primary processor
   is always booted regardless of the setting of the corresponding
   bit in the CPU bitmap.

   To change the value of SMP_CPU_BITMAP in SYSBOOT or SYSGEN,
   specify a list of individual bits or contiguous groups of bits.
   For example:

      SYSGEN> SET SMP_CPU_BITMAP 0,5,17-21

   The command in this example sets bits 0, 5, 17, 18, 19, 20, and
   21 in the bitmap and clears all other bits.

   This parameter replaces the SMP_CPUS parameter.
 

2  SMP_LNGSPINWAIT
   SMP_LNGSPINWAIT establishes, in 10-microsecond intervals, the
   amount of time a CPU in an SMP system normally waits for access
   to a shared resource. This process is called spinwaiting.

   Generally spinlocks at IPL <= 8 have long holding times,
   therefore have their timeout intervals set to SMP_LNGSPINWAIT
   to prevent SPINWAIT timeouts in cases of nested acquisition.

   A timeout causes a CPUSPINWAIT bugcheck.

   The default value is 3000000 (30,00, 000 10-microsecond intervals
   or 30 second).
 

2  SMP_SANITY_CNT
   SMP_SANITY_CNT establishes, in 10-millisecond intervals, the
   timeout period for each CPU in a symmetric multiprocessing (SMP)
   system. Each CPU in an SMP system monitors the sanity timer of
   one other CPU in the configuration to detect hardware or software
   failures. If allowed to go undetected, these failures could cause
   the cluster to hang. A timeout causes a CPUSANITY bugcheck.

   The default value is 300 milliseconds (30 10-millisecond
   intervals).
 

2  SMP_SPINWAIT
   SMP_SPINWAIT establishes, in 10-microsecond intervals, the amount
   of time a CPU in an SMP system normally waits for access to a
   shared resource. This process is called spinwaiting.

   A timeout causes a CPUSPINWAIT bugcheck.

   The default value is 100000 (100,000 10-microsecond intervals or
   1 second).
 

2  SMP_TICK_CNT
   SMP_TICK_CNT sets the frequency of sanity timer checks by each
   CPU in a multiprocessing system.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  SSI_ENABLE
   (Integrity servers only) This parameter controls the usage of
   system service interception. SSI_ENABLE is turned on by default.

   System Service Interception is a mechanism that allows user
   specified code to run before, after or instead of the intercepted
   system service. This mechanism is available on OpenVMS Alpha
   Version 6.1 and later and OpenVMS Integrity servers Version
   8.3 and later, but the parameter SSI_ENABLE is relevant only
   on Integrity server systems.
 

2  SSINHIBIT
   SSINHIBIT controls whether system services are inhibited (1)
   (on a per-process basis). By default, system services are not
   inhibited (0).

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  STARTUP_P1-8
   The following table describes possible values of STARTUP_P1
   through _P8:

   STARTUP
   Value          Description

   STARTUP_P1     Specifies the type of system boot the system-
                  independent startup procedure is to perform when
                  STARTUP_P1 has one of the following values:

                  o  " "- A full boot is performed.

                  o  "MIN"- A minimum boot that starts only what is
                     absolutely necessary for the operating system
                     to run.

   STARTUP_P2     Controls the setting of verification during the
                  execution of the system-independent startup
                  procedure, STARTUP.COM, when STARTUP_P2 has one
                  of the values described in the lists below.

                  STARTUP_P2 can be one of the values shown in the
                  following list:

                  o  F[ALSE], N[O], 0, " "-Verification is not
                     enabled; in other words, NOVERIFY is performed.

                  o  T[RUE], Y[ES], 1-Verification is enabled; in
                     other words, a SET VERIFY is performed.

                  Alternatively, STARTUP_P2 can be a string
                  containing one or more of the letters shown in
                  the following list:

                  o  C-Display various checkpointing messages during
                     startup.

                  o  D-Log (or Dump) the output from the startup to
                     a file called SYS$SPECIFIC:[SYSEXE]STARTUP.LOG.

                  o  P-DCL verification is enabled for each
                     component file, but not for the startup driver.
                     If both P and V are used, P is ignored.

                  o  V-Full DCL verification is enabled; same as
                     TRUE.

                  For more information about STARTUP_P2, see the
                  SYSMAN command STARTUP SET OPTIONS.
   STARTUP_P3     Beginning in OpenVMS Version 7.2, if STARTUP_P3
                  is set to AGEN, the system executes AUTOGEN at the
                  end of the startup sequence.

   STARTUP_P4     Reserved for future use.
   through
   STARTUP_P8
 

2  SWP_PRIO
   SWP_PRIO sets the priority of I/O transfers initiated by the
   swapper.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  SWPFAIL
   SWPFAIL sets the number of consecutive swap failures allowed
   before the swap schedule algorithm is changed to ignore the swap
   quantum protection.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  SWPOUTPGCNT
   This parameter allows the swapper an alternative mechanism before
   actually performing swaps.

   On Alpha and Integrity servers, SWPOUTPGCNT defines the minimum
   number of pagelets to which the swapper should attempt to reduce
   a process before swapping it out. The pagelets taken from the
   process are placed into the free-page list.

   SWPOUTPGCNT has the DYNAMIC attribute. On VAX systems,
   SWPOUTPGCNT also has the AUTOGEN attribute.
 

2  SWPRATE
   SWPRATE sets the swapping rate (in 10-millisecond units).
   This parameter limits the amount of disk bandwidth consumed by
   swapping.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  SYSMWCNT
   SYSMWCNT sets the quota for the size of the system working set,
   which contains the pageable portions of the system, the paged
   dynamic pool, RMS, and the resident portion of the system message
   file.

   While a high value takes space away from user working sets, a low
   value can seriously impair system performance. Appropriate values
   vary, depending on the level of system use. When the system is
   running at full load, check the rate of system faults with the
   MONITOR PAGE command of the Monitor utility. An average system
   page fault rate of between 0 and 3 page faults per second is
   desirable. If the system page fault rate is high, and especially
   if the system seems to be slow, you should increase the value of
   SYSMWCNT. However, do not set this parameter so high that system
   page faulting never occurs.

   SYSMWCNT has the AUTOGEN, GEN, and MAJOR attributes.
 

2  SYSPFC
   SYSPFC sets the number of pages to be read from disk on each
   system paging operation.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  SYSSER_LOGGING
   (Alpha and Integrity servers) A value of 1 for SYSSER_LOGGING
   enables logging of system service requests for a process. The
   default is 1.

   SYSSER_LOGGING is a DYNAMIC system parameter.
 

2  SYSTEM_CHECK
   SYSTEM_CHECK investigates intermittent system failures by
   enabling a number of run-time consistency checks on system
   operation and recording some trace information.

   Enabling SYSTEM_CHECK causes the system to behave as if the
   following system parameter values are set (although the values
   of the following parameters are not actually changed):

   Parameter        Value         Description

   BUGCHECKFATAL    1             Crash the system on nonfatal
                                  bugchecks.

   POOLCHECK        %X616400FF    Enable all poolchecking, with
                                  an allocated pool pattern
                                  of %x61616161 ('aaaa') and
                                  deallocated pool pattern of
                                  x64646464 ('dddd').

   MULTIPROCESSING  2             Enable full synchronization
                                  checking.

   While SYSTEM_CHECK is enabled, the previous settings of the
   BUGCHECKFATAL and MULTIPROCESSING parameters are ignored.
   However, setting the parameter POOLCHECK to a nonzero value
   overrides the setting imposed by SYSTEM_CHECK.

   Setting SYSTEM_CHECK creates certain image files that are capable
   of the additional system monitoring. These image files are
   located in SYS$LOADABLE_IMAGES and can be identified by the
   suffix _MON. For information about the type of data checking
   performed by SYSTEM_CHECK, see the description of the ACP_
   DATACHECK parameter. For information about the performance
   implications of enabling SYSTEM_CHECK, see OpenVMS Performance
   Management.
 

2  TAPE_ALLOCLASS
   TAPE_ALLOCLASS determines the tape allocation class for the
   system. The tape allocation class creates a unique clusterwide
   device name for multiple access paths to the same tape.

   The TAPE_ALLOCLASS parameter can also be used to generate a
   unique clusterwide name for tape devices with identical unit
   numbers.
 

2  TAPE_MVTIMEOUT
   TAPE_MVTIMEOUT is the time in seconds that a mount verification
   attempt continues on a given magnetic tape volume. If the mount
   verification does not recover the volume within that time, the
   I/O operations outstanding to the volume terminate abnormally.

   TAPE_MVTIMEOUT is a DYNAMIC parameter.
 

2  TBSKIPWSL
   TBSKIPWSL specifies the maximum number of working set list
   entries that may be skipped while scanning for a "good" entry
   to discard. Setting this parameter to 0 disables skipping.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  TIME_CONTROL
   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   TIME_CONTROL is an SMP bit mask parameter that controls debugging
   functions. The following bits are defined:

   Bit                    Description

   0                      Obsolete.

   1 (EXE$V_SANITY)       Disables the SMP sanity timer support.

   2 (EXE$V_NOSPINWAIT)   Disables the functional behavior of the
                          SMP spinwait support.

   TIME_CONTROL is a DYNAMIC parameter.
 

2  TIMEPROMPTWAIT
   TIMEPROMPTWAIT defines the number of seconds that you want a
   processor to wait for the time and date to be entered when a
   system boot occurs, if the processor's time-of-year clock does
   not contain a valid time. (The time unit of micro-fortnights
   is approximated as seconds in the implementation.) If the
   time specified by TIMEPROMPTWAIT elapses, the system continues
   the boot operation, and the date and time are set to the last
   recorded time that the system booted.

                                  NOTE

      VSI recommends that you set the correct system time before
      allowing the system to run, so that all functions using
      time-stamping (such as the operator log, the error log,
      accounting records, file creation dates, and file expiration
      dates) contain correct time values.

   Depending on the value specified for the TIMEPROMPTWAIT
   parameter, the system acts in one of the following ways:

   o  If TIMEPROMPTWAIT is 0, no prompt or wait occurs; the system
      boots immediately, using the time of the last boot as the
      system time.

   o  If TIMEPROMPTWAIT is a positive number less than 32768, one
      prompt is issued and the value dictates how many seconds you
      can take to respond with a time. If you do not provide a time
      before TIMEPROMPTWAIT elapses, the system boots, using the
      time of the last boot as the system time.

   o  If TIMEPROMPTWAIT is a number in the range of 32768 through
      65535, the prompt for the time is issued at intervals starting
      with 2 and doubling until 256 seconds is reached. If no
      response is received, the prompts restart, with the 2-second
      interval. This prompting process repeats indefinitely, until
      you specify a time.
 

2  TIMVCFAIL
   TIMVCFAIL specifies the time required for an adapter or virtual
   circuit failure to be detected. VSI recommends that the default
   value be used. VSI also recommends that this value be lowered only
   in OpenVMS Cluster of three CPUs or less, that the same value
   be used on each computer in the cluster, and that dedicated LAN
   segments be used for cluster I/O.

   TIMVCFAIL is a DYNAMIC parameter.
 

2  TMSCP_LOAD
   TMSCP_LOAD allows the loading of the tape mass storage control
   protocol server software. The TMSCP_LOAD parameter also sets
   locally connected tapes served. For information about setting the
   TMSCP_LOAD parameter, see VSI OpenVMS Cluster Systems.

   Setting TMSCP_LOAD to 0 inhibits the loading of the tape server
   and the serving of local tapes. Setting TMSCP to 1 loads the
   tape server into memory at the time the system is booted and
   makes all directly connected tape drives available clusterwide.
   The following table describes the two states of the TMSCP_LOAD
   parameter:

   State  Function

   0      Do not load the TMSCP tape server. Do not serve any local
          tape devices clusterwide. This is the default value.

   1      Load the TMSCP tape server. Serve all local TMSCP tape
          devices clusterwide.

   TMSCP_LOAD is an AUTOGEN parameter.
 

2  TMSCP_SERVE_ALL
   TMSCP_SERVE_ALL is a bit mask that controls the serving of tapes.
   The settings take effect when the system boots. You cannot change
   the settings when the system is running.

   Starting with OpenVMS Version 7.2, the serving types are
   implemented as a bit mask. To specify the type of serving your
   system will perform, locate the type you want in the following
   table and specify its value. For some systems, you may want
   to specify two serving types, such as serving all tapes except
   those whose allocation class does not match. To specify such a
   combination, add the values of each type, and specify the sum.

   In a mixed-version cluster that includes any systems running
   OpenVMS Version 7.1-x or earlier, serving all available tapes
   is restricted to serving all tapes except those whose allocation
   class does not match the system's allocation class (pre-Version
   7.2 meaning). To specify this type of serving, use the value 9,
   which sets bit 0 and bit 3. The following table describes the
   serving type controlled by each bit and its decimal value:

          Value
          When
   Bit    Set     Description

   Bit 0  1       Serve all available tapes (locally attached and
                  those connected to HSx and DSSI controllers).
                  Tapes with allocation classes that differ from the
                  system's allocation class (set by the ALLOCLASS
                  parameter) are also served if bit 3 is not set.

   Bit 1  2       Serve locally attached (non-HSx and non-DSSI)
                  tapes.

   Bit 2  N/A     Reserved.

   Bit 3  8       Restrict the serving specified by bit 0. All tapes
                  except those with allocation classes that differ
                  from the system's allocation class (set by the
                  ALLOCLASS parameter) are served.

                  This is pre-Version 7.2 behavior. If your cluster
                  includes systems running OpenVMS Version 7.1-x
                  or earlier, and you want to serve all available
                  tapes, you must specify 9, the result of setting
                  this bit and bit 0.

   Although the serving types are now implemented as a bit mask, the
   values of 0, 1, and 2, specified by bit 0 and bit 1, retain their
   original meanings:

   o  0 - Do not serve any tapes (the default for earlier versions
      of OpenVMS).

   o  1 - Serve all available tapes.

   o  2 - Serve only locally attached (non-HSx and non-DSSI) tapes.

   If the TMSCP_LOAD system parameter is 0, TMSCP_SERVE_ALL is
   ignored.
 

2  TTY_ALTALARM
   TTY_ALTALARM sets the size of the alternate type-ahead buffer
   alarm. This value indicates at what point an XOFF should be sent
   to terminals that use the alternate type-ahead buffers with the
   size specified by the TTY_ALTYPAHD parameter.
 

2  TTY_ALTYPAHD
   TTY_ALTYPAHD sets the size of the alternate type-ahead buffer.
   Use this parameter to allow the block mode terminals and
   communications lines to operate more efficiently.

   The default value is usually adequate. Do not exceed the maximum
   value of 32767 when setting this parameter.
 

2  TTY_AUTOCHAR
   TTY_AUTOCHAR sets the character the terminal driver echoes when
   the job controller has been notified.

   TTY_AUTOCHAR is a DYNAMIC parameter.
 

2  TTY_BUF
   TTY_BUF sets the default line width for terminals.
 

2  TTY_CLASSNAME
   TTY_CLASSNAME provides the 2-character prefix for the terminal
   class driver name that is required when booting. Changing the
   prefix can be useful when debugging a new terminal driver.
 

2  TTY_DEFCHAR
   TTY_DEFCHAR sets the default characteristics for terminals, using
   a code derived by summing the following hexadecimal values:

   Characteristic   Value (Hex)     Function

   PASSALL                 1        Passall.
   NOECHO                  2        Noecho mode.
   NOTYPEAHEAD             4        No type-ahead buffer.
   ESCAPE                  8        Escape sequence processing.
   HOSTSYNC               10        Host can send XON and XOFF.
   TTSYNC                 20        Terminal can send XON and XOFF.
   SCRIPT                 40        Internal use only.
   LOWER                  80        Lowercase.
   MECHTAB               100        Mechanical tabs.
   WRAP                  200        Wraparound at end of line.
   CRFILL                400        Perform carriage return fill.
   LFFILL                800        Perform line feed fill.
   SCOPE                1000        Terminal is a scope.
   REMOTE               2000        Internal use only.
   EIGHTBIT             8000        Eight-bit terminal.
   MBXDSABL            10000        Disable mailbox.
   NOBRDCST            20000        Prohibit broadcast.
   READSYNC            40000        XON and XOFF on reads.
   MECHFORM            80000        Mechanical form feeds.
   HALFDUP            100000        Set for half-duplex operation.
   MODEM              200000        Set for modem signals.
   PAGE             FF000000        Page size. Default is 24.

   Do not set the CRFILL or LRFILL characteristic as the default in
   TTY_DEFCHAR.

   Where a condition is false, the value is 0.

   The upper byte is the page length. The default characteristics
   are 24 lines per page, terminal synchronization, wraparound,
   lowercase, scope, and full-duplex.
 

2  TTY_DEFCHAR2
   TTY_DEFCHAR2 sets a second longword of default terminal
   characteristics. The default characteristics are represented
   as a code that is derived by summing the following hexadecimal
   values:

   Characteristic Value (Hex)   Function

   LOCALECHO             1      Enable local echo terminal logic;
                                use with the TTY_DEFCHAR NOECHO
                                characteristic.
   AUTOBAUD              2      Enable autobaud detection.
   HANGUP                4      Hang up on logout.
   MODHANGUP             8      Allow modification of HANGUP without
                                privileges.
   BRDCSTMBX            10      Allow sending of broadcasts to
                                mailboxes.
   XON                  20      (No effect in this parameter.)
   DMA                  40      (No effect in this parameter.)
   ALTYPEAHD            80      Use the alternate type-ahead
                                parameters.
   SETSPEED            100      Clear to allow setting of speed
                                without privileges.
   DCL_MAILBX          200      Function reserved for VSI use only.
   DECCRT4             400      Terminal is DIGITAL CRT Level 4.
   COMMSYNC            800      Enable flow control using modem
                                signals.
   EDITING            1000      Line editing allowed.
   INSERT             2000      Sets default mode for insert.
   FALLBACK           4000      Do not set this bit with SYSGEN.
   DIALUP             8000      Terminal is a dialup line.
   SECURE            10000      Guarantees that no process is
                                connected to terminal after Break
                                key is pressed.
   DISCONNECT        20000      Allows terminal disconnect when a
                                hangup occurs.
   PASTHRU           40000      Terminal is in PASTHRU mode.
   SYSPWD            80000      Log in with system password only.
   SIXEL            100000      Sixel graphics.
   DRCS             200000      Terminal supports loadable character
                                fonts.
   PRINTER          400000      Terminal has printer port.
   APP_KEYPAD       800000      Notifies application programs of
                                state to set keypad on exit.
   ANSICRT         1000000      Terminal conforms to ANSI CRT
                                programming standards.
   REGIS           2000000      Terminal has REGIS CRT capabilities.
   BLOCK           4000000      Block mode terminal.
   AVO             8000000      Terminal has advanced video.
   EDIT           10000000      Terminal has local edit
                                capabilities.
   DECCRT         20000000      Terminal is a DIGITAL CRT.
   DECCRT2        40000000      Terminal is a DIGITAL CRT Level 2.
   DECCRT3        80000000      Terminal is a DIGITAL CRT Level 3.

   The defaults are AUTOBAUD and EDITING.
 

2  TTY_DEFCHAR3
   (Alpha and Integrity servers) TTY_DEFCHAR3 allows a user to set a
   bit so that the OpenVMS terminal driver remaps CTRL/H to Delete.
   VSI recommends that you not set this bit as a systemwide default.

   Characteristic Value (Hex)   Function

   TT3$M_BS             10      When this bit is set, the OpenVMS
                                terminal console remaps CTRL/H to
                                Delete.

   For more information, see the SET TERM and SHOW TERM commands in
   the VSI OpenVMS DCL Dictionary.
 

2  TTY_DEFPORT
   TTY_DEFPORT provides flag bits for port drivers. Bit 0 set
   to 1 indicates that the terminal controller does not provide
   automatic XON/XOFF flow control. This bit should not be set for
   VSI Controllers, but it is needed for some foreign controllers.
   Currently only the YCDRIVER (DMF32, DMZ32) uses this bit.
   The remaining bits are reserved for future use. This special
   parameter should be modified only if recommended by VSI.
 

2  TTY_DIALTYPE
   TTY_DIALTYPE provides flag bits for dialups. Bit 0 is 1 for
   United Kingdom dialups and 0 for all others. Bit 1 controls the
   modem protocol used. Bit 2 controls whether a modem line hangs
   up 30 seconds after seeing CARRIER if a channel is not assigned
   to the device. The remaining bits are reserved for future use.
   See the OpenVMS I/O User's Reference Manual for more information
   about flag bits.
 

2  TTY_DMASIZE
   TTY_DMASIZE specifies a number of characters in the output
   buffer. Below this number, character transfers are performed;
   above this number, DMA transfers occur if the controller is
   capable of DMA I/O.

   TTY_DMASIZE is a DYNAMIC parameter.
 

2  TTY_PARITY
   TTY_PARITY sets terminal default parity.
 

2  TTY_RSPEED
   TTY_RSPEED defines the receive speed for terminals. If TTY_
   RSPEED is 0, TTY_SPEED controls both the transmit and the receive
   speed. Maximum value is 20. This parameter is only applicable for
   controllers that support split-speed operations, such as the DZ32
   and the DMF32.
 

2  TTY_SCANDELTA
   TTY_SCANDELTA sets the interval for polling terminals for dialup
   and hangup events. Shorter intervals use more processor time;
   longer intervals may result in missing a hangup event.
 

2  TTY_SILOTIME
   TTY_SILOTIME defines the interval at which the DMF32 hardware
   polls the input silo for received characters. The DMF32
   asynchronous terminal controller can delay the generation
   of a single input interrupt until multiple characters have
   accumulated in the input silo. TTY_SILOTIME specifies the number
   of milliseconds that the characters are allowed to accumulate
   prior to the generation of an input interrupt by the hardware.

                                  NOTE

      The remainder of this discussion is of interest to customers
      who use Digi Edgeport hardware.

   TTY_SILOTIME controls latency, trading throughput and system
   overhead for latency. The default value for TTY_SILOTIME is 8.
   This value is multiplied by 100 and is used as a count of the
   number of times to send a query to the device for more data after
   a character transmit or receive is performed.

   If no input (or no subsequent output) is seen after 800 responses
   to the query, the driver stops sending queries to the device and
   waits for an input interrupt. Reducing the TTY_SILOTIME value
   allows the device to buffer more data, with slightly higher
   latency.

   Increasing the value of TTY_SILOTIME makes the device more
   sensitive to latency but decreases buffering and overall
   throughput; it also adds more system and USB overhead. Setting
   TTY_SILOTIME to zero causes the driver to send input queries to
   the device continually. This setting causes the lowest latency,
   the highest system overhead, and the lowest throughput possible.
 

2  TTY_SPEED
   TTY_SPEED sets the systemwide default speed for terminals. Low
   byte is transmit speed, and high byte is receive speed. If high
   byte is set to 0, receive speed is identical to transmit speed.
   Maximum value is 20. Baud rates are defined by the $TTDEF macro.
 

2  TTY_TIMEOUT
   TTY_TIMEOUT sets the number of seconds before a process
   associated with a disconnected terminal is deleted. The default
   value (900 seconds) is usually adequate. Note that using values
   for TTY_TIMEOUT greater than one year (value %X01E13380) can
   cause overflow errors and result in a disconnected device timing
   out immediately.

   TTY_TIMEOUT is a DYNAMIC parameter.
 

2  TTY_TYPAHDSZ
   TTY_TYPAHDSZ sets the size of the terminal type-ahead buffer.
   The default value is usually adequate. Do not exceed the maximum
   value of 32767 when setting this parameter.
 

2  UAFALTERNATE
   UAFALTERNATE enables or disables the assignment of SYSUAF
   as the logical name for SYSUAFALT, causing all references
   to the user authorization file (SYSUAF) to be translated to
   SYS$SYSTEM:SYSUAFALT. Use of the normal user authorization file
   (SYS$SYSTEM:SYSUAF) can be restored by deassigning the system
   logical name SYSUAF. This parameter should be set on (1) only
   when the system is being used by a restricted set of users. You
   must create a user authorization file named SYSUAFALT prior to
   setting UAFALTERNATE to 1.

   UAFALTERNATE has the GEN and MAJOR attributes.
 

2  USERD1
   USERD1 is reserved for definition at the user's site. The
   reserved longword is referenced by the symbol SGN$GL_USERD1.

   On Alpha and Integrity servers, this symbol is in the
   SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module.

   USERD1 is a DYNAMIC parameter.
 

2  USERD2
   USERD2 is reserved for definition at the user's site. The
   reserved longword is referenced by the symbol SGN$GL_USERD2.

   On Alpha and Integrity servers, this symbol is in the
   SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module.

   USERD2 is a DYNAMIC parameter.
 

2  USER3
   USER3 is a parameter that is reserved for definition at the
   user's site. The reserved longword is referenced by the symbol
   SGN$GL_USER3.

   On Alpha and Integrity servers, this symbol is in the
   SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module.
 

2  USER4
   USER4 is a parameter that is reserved for definition at the
   user's site. The reserved longword is referenced by the symbol
   SGN$GL_USER4.

   On Alpha and Integrity servers, this symbol is in the
   SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module.
 

2  VAXCLUSTER
   VAXCLUSTER controls loading of the cluster code. Specify one of
   the following:

   Value  Description

   0      Never form or join a cluster.

   1      Base decision of whether to form (or join) a cluster or to
          operate standalone on the presence of cluster hardware.

   2      Always form or join a cluster.

   The default value is 1.

   VAXCLUSTER is an AUTOGEN parameter.
 

2  VCC_FLAGS
   (Alpha only) The static system parameter VCC_FLAGS enables and
   disables file system data caching. If caching is enabled, VCC_
   FLAGS controls which file system data cache is loaded during
   system startup.

   Value  Description

   0      Disables file system data caching on the local node and
          throughout the OpenVMS Cluster.

          In an OpenVMS Cluster, if caching is disabled on any node,
          none of the other nodes can use the extended file cache
          or the virtual I/O cache. They can't cache any file data
          until that node either leaves the cluster or reboots with
          VCC_FLAGS set to a nonzero value.

   1      Enables file system data caching and selects the Virtual
          I/O Cache. This is the default for VAX systems.

   2      Enables file system data caching and selects the extended
          file cache. This is the default for Alpha systems.

                                  NOTE

      On Integrity servers, the volume caching product
      ([SYS$LDR]SYS$VCC.EXE) is not available. XFC caching is the
      default caching mechanism. Setting the VCC_FLAGS parameter
      to 1 is equivalent to not loading caching at all or to
      setting VCC_FLAGS to 0.

   VCC_FLAGS is an AUTOGEN parameter.
 

2  VCC_MAXSIZE
   (Alpha and Integrity servers) The static system parameter VCC_
   MAXSIZE controls the size of the virtual I/O cache. VCC_MAXSIZE,
   which specifies the size in blocks, is 3,700,000 by default.

   The virtual I/O cache cannot shrink or grow. Its size is fixed at
   system startup.

   To adjust the XFC size, use the VCC_MAX_CACHE system parameter.

   VCC_MAXSIZE is an AUTOGEN parameter.
 

2  VCC_MAX_CACHE
   (Alpha and Integrity servers) The dynamic system parameter VCC_
   MAX_CACHE controls the maximum size of the extended file cache.
   It specifies the size in megabytes. By default, VCC_MAX_CACHE has
   a special value of -1 for people who do not want to tune their
   systems manually; this value means that at system startup, the
   maximum size of the extended file cache is set to 50 percent of
   the physical memory on the system.

   The extended file cache can automatically shrink and grow,
   depending on your I/O workload and how much spare memory
   your system has. As your I/O workload increases, the cache
   automatically grows, but never to more than the maximum size.
   When your application needs memory, the cache automatically
   shrinks.

   The value of VCC_MAX_CACHE at system startup sets an upper limit
   for the maximum size of the extended file cache. You cannot
   increase the maximum size of VCC_MAX_CACHE beyond its value
   at boot time. For example, if VCC_MAX_CACHE is 60 MB at system
   startup, you can then set VCC_MAX_CACHE to 40, which decreases
   the maximum size to 40 MB. If you then set VCC_MAX_CACHE to 80,
   the maximum size is only increased to 60 MB, the value set at
   system startup.

   Note that VCC_MAX_CACHE is a semi-dynamic parameter. If you
   change its value, you must enter the DCL command SET CACHE/RESET
   for any changes to take effect immediately. Otherwise, it might
   take much more time for the changes to take effect.

   If you are using the reserved memory registry to allocate
   memory permanently, you must set the VCC$MIN_CACHE_SIZE entry
   in the reserved memory registry to a value less than or equal to
   VCC_MAX_CACHE at system startup time.

   For instructions on setting permanent memory allocations for the
   cache, see the VSI OpenVMS System Manager's Manual.

   VCC_MAX_CACHE is a DYNAMIC parameter.
 

2  VCC_MAX_IO_SIZE
   (Alpha and Integrity servers) The dynamic system parameter VCC_
   MAX_IO_SIZE controls the maximum size of I/O that can be cached
   by the extended file cache. It specifies the size in blocks. By
   default, the size is 127 blocks.

   Changing the value of VCC_MAX_IO_SIZE affects reads and writes to
   volumes currently mounted on the local node, as well as reads and
   writes to volumes mounted in the future.

   If VCC_MAX_IO_SIZE is 0, the extended file cache on the local
   node cannot cache any reads or writes. However, the system is
   not prevented from reserving memory for the extended file cache
   during startup if a VCC$MIN_CACHE_SIZE entry is in the reserved
   memory registry.

   VCC_MAX_IO_SIZE is a DYNAMIC parameter.
 

2  VCC_MAX_LOCKS
   (Alpha and Integrity servers) VCC_MAX_LOCKS is a special
   parameter reserved for VSI use only. Extended file cache will
   use this parameter in future versions.
 

2  VCC_PAGESIZE
   (Alpha and Integrity servers) VCC_PAGESIZE is a special parameter
   reserved for VSI use only. Extended file cache will use this
   parameter in future versions.
 

2  VCC_READAHEAD
   (Alpha and Integrity servers) The dynamic system parameter VCC_
   READAHEAD controls whether the extended file cache can use read-
   ahead caching. Read-ahead caching is a technique that improves
   the performance of applications that read data sequentially.

   By default VCC_READAHEAD is 1, which means that the extended file
   cache can use read-ahead caching. The extended file cache detects
   when a file is being read sequentially in equal-sized I/Os, and
   fetches data ahead of the current read, so that the next read
   instruction can be satisfied from cache.

   To stop the extended file cache from using read-ahead caching,
   set VCC_READAHEAD to 0.

   Changing the value of VCC_READAHEAD affects volumes currently
   mounted on the local node, as well as volumes mounted in the
   future.

   Readahead I/Os are totally asynchronous from user I/Os and only
   take place if sufficient system resources are available.

   VCC_READAHEAD is a DYNAMIC parameter.
 

2  VCC_RSVD
   (Alpha and Integrity servers) VCC_RSVD is a special parameter
   reserved for VSI use only. Extended file cache will use this
   parameter in future versions.
 

2  VCC_WRITEBEHIND
   (Alpha and Integrity servers) VCC_WRITEBEHIND is reserved for VSI
   use only. Extended file cache will use this parameter in future
   versions.
 

2  VCC_WRITE_DELAY
   (Alpha and Integrity servers) VCC_WRITE_DELAY is reserved for VSI
   use only.
 

2  VHPT_SIZE
   (Integrity servers only) VHPT_SIZE is the number of kilobytes to
   allocate for the virtual hash page table (VHPT) on each CPU in
   the system:

   o  0 indicates that no VHPT is allocated.

   o  1 indicates that OpenVMS is to choose a default size that is
      appropriate for your system configuration.

   If a VHPT is created, the smallest size is 32KB. The VHPT_SIZE
   must be a power of 2 KB in size. If the number specified is not
   a power of 2, OpenVMS chooses a VHPT size to use for your system
   that is close to the number specified.

   If insufficient memory is available during system startup,
   OpenVMS might choose a smaller size for the VHPT of each CPU.

   A summary of possible values for VHPT_SIZE is in the following
   table:

   Value Description

   0     Do not create a VHPT on each CPU.
   1     (default) OpenVMS chooses a VHPT of an appropriate size for
         each CPU.
   n     Create a VHPT of nKB for each CPU, where n is a power of
         2 that is 32 or greater. (The maximum value, however, is
         platform-dependent.)
 

2  VIRTUALPAGECNT
   On VAX systems, VIRTUALPAGECNT sets the maximum number of virtual
   pages that can be mapped for any one process. A program is
   allowed to divide its virtual space between the P0 and P1 tables
   in any proportion.

   If you use SYS$UPDATE:LIBDECOMP.COM to decompress libraries
   and the VIRTUALPAGECNT setting is low, make sure you set the
   PGFLQUOTA field in the user authorization file to at least twice
   the size of the library.

   At installation time, AUTOGEN automatically sets an appropriate
   value for VIRTUALPAGECNT. The value depends on the particular
   configuration-the type and number of graphics adapters on the
   system, if any exist. You cannot set VIRTUALPAGECNT below the
   minimum value required for your graphics configuration.

   Because the VIRTUALPAGECNT setting supports hardware address
   space rather than system memory, do not use the value of
   VIRTUALPAGECNT that AUTOGEN sets to gauge the size of your page
   file.

   Starting with OpenVMS Version 7.0, VIRTUALPAGECNT has been an
   obsolete parameter on Alpha systems. Note, however, that the
   parameter remains in existence on Alpha and Integrity servers
   for compatibility purposes and has a default and maximum value of
   %X7FFFFFFF. SYSBOOT and AUTOGEN enforce this default value.

   VIRTUALPAGECNT has the AUTOGEN, GEN, and MAJOR attributes.
 

2  VMS1-8
   VMSD1, VMSD2, VMSD3, VMSD4, VMS5, VMS6, VMS7, and VMS8 are
   special parameters reserved for VSI use. VMSD1 through VMSD4 are
   DYNAMIC.
 

2  VOTES
   VOTES establishes the number of votes an OpenVMS Cluster member
   system contributes to a quorum.

   VOTES has the AUTOGEN attribute.
 

2  WBM_MSG_INT
   WBM_MSG_INT is one of three system parameters that are available
   for managing the update traffic between a master write bitmap
   and its corresponding local write bitmaps in an OpenVMS Cluster
   system. The others are WBM_MSG_UPPER and WBM_MSG_LOWER. These
   parameters set the interval at which the frequency of sending
   messages is tested and also set an upper and lower threshold that
   determine whether the messages are grouped into one SCS message
   or are sent one by one.

   In single-message mode, WBM_MSG_INT is the time interval in
   milliseconds between assessments of the most suitable write
   bitmap message mode. In single-message mode, the writes issued by
   each remote node are, by default, sent one by one in individual
   SCS messages to the node with the master write bitmap. If
   the writes sent by a remote node reach an upper threshhold
   of messages during a specified interval, single-message mode
   switches to buffered-message mode.

   In buffered-message mode, WBM_MSG_INT is the maximum time a
   message waits before it is sent. In buffered-message mode, the
   messages are collected for a specified interval and then sent
   in one SCS message. During periods of increased message traffic,
   grouping multiple messages to send in one SCS message to the
   master write bitmap is generally more efficient than sending each
   message separately.

   The minimum value of WBM_MSG_INT is 10 milliseconds. The maximum
   value is -1, which corresponds to the maximum positive value that
   a longword can represent. The default is 10 milliseconds.

   WBM_MSG_INT is a DYNAMIC parameter.
 

2  WBM_MSG_LOWER
   WBM_MSG_LOWER is one of three system parameters that are
   available for managing the update traffic between a master
   write bitmap and its corresponding local write bitmaps in an
   OpenVMS Cluster system. The others are WBM_MSG_INT and WBM_MSG_
   UPPER. These parameters set the interval at which the frequency
   of sending messages is tested and also set an upper and lower
   threshold that determine whether the messages are grouped into
   one SCS message or are sent one by one.

   WBM_MSG_LOWER is the lower threshold for the number of messages
   sent during the test interval that initiates single-message mode.
   In single-message mode, the writes issued by each remote node
   are, by default, sent one by one in individual SCS messages to
   the node with the master write bitmap. If the writes sent by
   a remote node reach an upper threshhold of messages during a
   specified interval, single-message mode switches to buffered-
   message mode.

   The minimum value of WBM_MSG_LOWER is 0 messages per interval.
   The maximum value is -1, which corresponds to the maximum
   positive value that a longword can represent. The default is
   10.

   WBM_MSG_LOWER is a DYNAMIC parameter.
 

2  WBM_MSG_UPPER
   WBM_MSG_UPPER is one of three system parameters that are
   available for managing the update traffic between a master
   write bitmap and its corresponding local write bitmaps in an
   OpenVMS Cluster system. The others are WBM_MSG_INT and WBM_MSG_
   LOWER. These parameters set the interval at which the frequency
   of sending messages is tested and also set an upper and lower
   threshold that determine whether the messages are grouped into
   one SCS message or are sent one by one.

   WBM_MSG_UPPER is the upper threshold for the number of messages
   sent during the test interval that initiates buffered-message
   mode. In buffered-message mode, the messages are collected for a
   specified interval and then sent in one SCS message.

   The minimum value of WBM_MSG_UPPER is 0 messages per interval.
   The maximum value is -1, which corresponds to the maximum
   positive value that a longword can represent. The default is
   100 seconds.

   WBM_MSG_UPPER is a DYNAMIC parameter.
 

2  WBM_OPCOM_LVL
   WBM_OPCOM_LVL controls whether write bitmap system messages are
   sent to the operator console. Possible values are shown in the
   following table:

   Value Description

   0     Messages are turned off.

   1     The default; messages are provided when write bitmaps are
         started, deleted, and renamed, and when the SCS message
         mode (buffered or single) changes.

   2     All messages for a setting of 1 are provided plus many
         more.

   WBM_OPCOM_LVL is a DYNAMIC parameter.
 

2  WINDOW_SYSTEM
   WINDOW_SYSTEM specifies the windowing system to be used on a
   workstation. Specify one of the following values:

   Value  Description

   1      Load the DECwindows Motif for OpenVMS workstation
          environment.

   2      Load the UIS workstation environment.

   WINDOW_SYSTEM is a DYNAMIC parameter.
 

2  WLKSYSDSK
   (Alpha and Integrity servers) WLKSYSDSK is used by various
   bootstrap components to determine if the system disk should be
   treated as though it is write-locked. This parameter is used
   primarily to allow OpenVMS to boot from a CD.
 

2  WPRE_SIZE
   WPRE_SIZE represents the number of pages to be allocated to
   accommodate WatchPoint Recovery Entries (WPRE) on the Watchpoint
   Driver.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   WPRE_SIZE is a DYNAMIC parameter.
 

2  WPTTE_SIZE
   WPTTE_SIZE is the number of entries that the WPDRIVER creates in
   the WatchPoint Trace Table.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   WPTTE_SIZE is a DYNAMIC parameter.
 

2  WRITABLESYS
   WRITABLESYS controls whether system code is writable. This
   parameter is set (value of 1) for debugging purposes only.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  WRITESYSPARAMS

   On Alpha and Integrity servers, WRITESYSPARAMS indicates that
   parameters are modified during SYSBOOT and are written out to
   ALPHAVMSSYS.PAR by STARTUP.COM.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.

   WRITESYSPARAMS is a DYNAMIC parameter.
 

2  WSDEC
   Increasing the value of this parameter tends to increase the
   speed with which working set limits are decreased when the need
   arises.

   On Alpha and Integrity servers, WSDEC specifies the number of
   pagelets by which the limit of a working set is automatically
   decreased at each adjustment interval (which is quantum end). At
   a setting of 35, for example, the system decreases the limit of a
   working set by 35 pagelets each time a decrease is required.

   WSDEC has the AUTOGEN, DYNAMIC, and MAJOR attributes.
 

2  WSINC
   Decreasing the value of this parameter tends to reduce the speed
   with which working set limits are increased when the need arises.
   Normally, you should keep this parameter at a high value because
   a rapid increase in limit is often critical to performance.

   On Alpha and Integrity servers, WSINC specifies the number of
   pagelets by which the limit of a working set is automatically
   increased at each adjustment interval (which is quantum end). At
   a setting of 150, for example, the system increases the limit of
   a working set by 150 pagelets each time an increase is required.
   On Alpha and Integrity servers, the default value is 2400 512-
   byte pagelets (150 8192-byte Alpha and Integrity server pages).

   A value of 0 for WSINC disables the automatic adjustment of
   working set limits for all processes. Limits stay at their base
   values. You can disable the automatic adjustment of working
   set limits on a per-process basis by using the DCL command SET
   WORKING_SET.

   WSINC has the DYNAMIC and MAJOR attributes. On Alpha and
   Integrity servers, WSINC also has the AUTOGEN attribute.
 

2  WSMAX
   WSMAX sets the maximum number of pages on a systemwide basis for
   any working set. WSMAX is calculated as a quarter of the first
   32 MB plus a sixteenth of the memory from 32 to 256 MB, plus a
   sixty-fourth of the memory (if any) above 256 MB.

   This is intended to assist managers of systems that host large
   numbers of users whose working sets are not large. Systems whose
   user bases consist of a small number of users (or processes)
   that require large amounts of physical memory (for example,
   simulations) might need to set MIN_WSMAX to a value that
   satisfies the requirements of those processes.

   WSMAX has the AUTOGEN, GEN, and MAJOR attributes.
 

2  XQPCTL2
   XQPCTL2 controls improved concurrency. The default value of
   XQPCTL2 is 1, which turns on improved concurrency. Setting
   XQPCTL2 to 0 turns off improved concurrency. This parameter
   affects local access to the extent and file ID caches.

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  XQPCTLD1
   XQPCTLD1 controls multithreading, which can be used only
   by PATHWORKS servers. The default value of XQPCTLD1 is 8,
   which enables multithreading. Setting XQPCTLD1 to 0 disables
   multithreading,

   This special parameter is use by VSI and is subject to change. Do
   not change this parameter unless VSI recommends that you do so.
 

2  ZERO_LIST_HI
   (Alpha and Integrity servers) ZERO_LIST_HI is the maximum number
   of pages zeroed and put on the zeroed page list. This list is
   used as a cache of pages containing all zeros, which improves the
   performance of allocating such pages.

   ZERO_LIST_HI has the AUTOGEN and DYNAMIC attributes.

! *********************************************************************
! PARAM-END! PARAM-INSERT
! HELP on the individual parameters is taken from SYSGEN and
! is inserted here by the build procedures. Please do not edit the
! first comment line.
!****************************************************************************

