$                               Compaq   Software Product  Description   C ___________________________________________________________________   C PRODUCT NAME:  DECram for OpenVMS Version 2.3                   SPD  34.26.07  $                               Compaq   Software Product  Description   C ___________________________________________________________________   C PRODUCT NAME:  DECram for OpenVMS Version 2.3                   SPD  34.26.07   DESCRIPTION   F DECram for OpenVMS Version 2.3 supports both the OpenVMS for Alpha and OpenVMS for VAX platforms.  D DECram for OpenVMS is a disk device driver that improves I/O perfor-B mance by allowing an OpenVMS system manager to create pseudo disks (RAMdisks), E which reside in main memory. Frequently accessed data can be accessed H much faster from a DECram device than from a physical disk device. TheseG RAMdisks can be accessed through the file system just as physical disks H are accessed, requiring no change to the application or the system soft- ware.   E Because main memory is allocated for a DECram device, extra memory is G generally required. The OpenVMS system manager can designate the amount C of memory dedicated to the DECram device(s) and the files that will  be stored on it.   Cluster Environment   C                                                       January, 1999          C DECram for OpenVMS Version 2.3 is fully supported when installed on C any valid and licensed standalone Alpha or VAX system, or any clus- D tered VAX system. DECram for OpenVMS Version 2.3 is required for any= OpenVMS Cluster systems running any version of OpenVMS Alpha.   E DECram for OpenVMS Version 2.3 supports operation in an Adaptive Par- I titioned Multi-Processing (APMP) environment, also known as Compaq Galaxy F Software Architecture on OpenVMS. Previous versions of DECram must notE be used if RAM disks are being served, or served and shadowed, across F nodes within a cluster, or if DECram is being used in an Adaptive Par-# titioned Multi-Processing instance.   F Multiple DECram devices can be members of a Volume Shadowing for Open-I VMS shadow set and can be served by mass storage control protocol (MSCP). F There are no special hardware requirements to install DECram for Open- VMS Version 2.3.   User Interface  E The user interface to a DECram device is the same as other disk class C devices. Note that the response to a SHOW DEVICE /FULL command will C indicate "device type unknown" in current OpenVMS releases. The de- F vice type DT$_RAM_DISK is not known by the SHOW DEVICE command in cur- rent OpenVMS releases.   Management Interface  E A DECram device is managed by the same tools used to manage any other C OpenVMS disk device. For example, the INITIALIZE, MOUNT, and DIREC- F TORY commands will work the same on both hard disk and DECram devices.D However, the standard utilities are used differently to set up a DE- Cram device.   System Analysis   D Before creating a DECram device, the OpenVMS system manager must de-C termine its size. Each disk block allocated to a DECram device will F mean one less page of available memory. The system manager should alsoF assess the need for multiple DECram units. See Restrictions listed be- low.  "                                  2          System Generation   E When adding a DECram device, the OpenVMS system manager must reassess E the values for the SYSGEN parameters that control paging and swapping 	 behavior.    Restrictions  C DECram for OpenVMS Version 2.3 currently has the following restric-  tions:  ' o  Data in a DECram device is volatile.   D o  Volume Shadowing for OpenVMS will support shadow sets composed ofD    DECram devices and other disk class devices, in a future release.G    Removal of the last non DECram device will cause the shadow set vir- F    tual unit to abort and become unavailable. Please refer to the Vol-H    ume Shadowing for OpenVMS Software Product Description (SPD 27.29.xx)    for more information.  D o  A single DECram device size on OpenVMS Alpha systems running Ver-)    sion 7.1 or higher is limited to 32GB.   E o  A single DECram device size on OpenVMS VAX systems running Version .    6.2 or higher is limited to 524,280 blocks.  G Note: For disk volumes larger than 524,280 blocks on VAX or 32GB on Al- F pha, multiple DECram disk devices can be created and bound into a vol- ume set.  E DECram for OpenVMS is not designed to support long-term data storage. E If a system or hardware failure occurs, data stored in the DECram de- D vice is lost and must be re-created. This restriction does not applyF if the device is shadowed to a real physical device, using a supported$ version of OpenVMS Volume Shadowing.          "                                  3          YEAR 2000 READINESS   C This product is capable of accurately processing, providing, and/or H receiving date data from, into and between the twentieth and the twenty-F first centuries, and the years 1999 and 2000, including leap year cal-C culations, when used in accordance with the associated product doc- E umentation and provided that all hardware, firmware and software used D in combination with the product properly exchange accurate date data with the product.    HARDWARE REQUIREMENTS   E Processor and hardware configurations as specified in the OpenVMS Op- B erating System Software for VAX and Alpha Product Description (SPD
 25.01.xx),6 or the appropriate operating system documentation set.   SOFTWARE REQUIREMENTS   C DECram for OpenVMS Version 2.3 supports OpenVMS for Alpha Operating D System Version 7.1 or higher. DECram for OpenVMS Version 2.3 is alsoE required for any OpenVMS Cluster systems running any version of Open- 
 VMS Alpha.  F DECram for OpenVMS Version 2.3 supports OpenVMS for VAX Operating Sys- tem Version 6.2 or higher.   ORDERING INFORMATION   OpenVMS for VAX    Software Licenses: QL-GJ9A*-** Software Media: QA-YL48A-H8 & Software Product Services: QT-GJ9A*-**  D DECram for OpenVMS Version 2.3 (for VAX) is distributed on the Open-C VMS VAX Software Product Library Distribution CD-ROMs (order number 
 QA-YL48A-H8).       "                                  4         8 DECram is no longer available on TK50 and magtape media.   OpenVMS for Alpha    Software Licenses: QL-MV3A*-** Software Media: QA-03XAA-H8 & Software Product Services: QT-MV3A*-**  F DECram for OpenVMS Version 2.3 (for Alpha) is distributed on the Open-C VMS Alpha Software Product Library Distribution CD-ROMs (order num-  ber QA-03XAA-H8).   F *  Denotes variant fields. For additional information on available li-D    censes, services, and media, refer to the appropriate price book.  F DECram for OpenVMS documentation is available in Bookreader, text, and PostScript[R] formats.   SOFTWARE LICENSING  C This software is furnished under the licensing provisions of Compaq E Computer Corporation's Standard Terms and Conditions. For more infor- D mation about Compaq's licensing terms and policies, contact your lo- cal Compaq office.  # License Management Facility Support   C This layered product supports the OpenVMS License Management Facil-  ity.  E License units for this product are allocated on a CPU-capacity basis.   E For more information on the License Management Facility, refer to the D OpenVMS Operating System for VAX and Alpha Software Product Descrip-C tion (SPD 25.01.xx), or the appropriate operating system documenta- 	 tion set.         "                                  5          SOFTWARE PRODUCT SERVICES   D A variety of service options are available from Compaq. For more in-, formation, contact your local Compaq office.   SOFTWARE WARRANTY   F This software is provided by Compaq with a 90 day conformance warrantyF in accordance with the Compaq warranty terms applicable to the license	 purchase.     A [R]  PostScript is a registered trademark of Adobe Systems Incor-       porated  > [TM] Bookreader, the Compaq Logo, Compaq, MSCP, OpenVMS, Open->      VMS Cluster, TK, VAX, VAXcluster, VMS, and VMScluster are/      trademarks of Compaq Computer Corporation.   8  1998 Compaq Computer Corporation. All rights reserved.                                        "                                  6