      Software Product  Description   C ___________________________________________________________________   C PRODUCT NAME:  RMS Journaling for OpenVMS, Version 7.3 SPD 27.58.13   D Note: This is the Software Product Description (SPD) for the follow- ing two products:   ! o  RMS Journaling for OpenVMS VAX   # o  RMS Journaling for OpenVMS Alpha   C Except where specifically noted, the features described in this SPD F apply to both products. The license and part number information is ar-E chitecture specific. Please refer to the Ordering Information section   of this SPD for further details.   DESCRIPTION   E RMS Journaling for OpenVMS helps maintain the data integrity of Open- C VMS RMS files and protects this file data from becoming lost or in- , consistent due to various failure scenarios.  H RMS Journaling for OpenVMS provides the following three methods of jour- naling:   C o  After-image (AI) journaling allows you to redo a series of modi- E    fications to a file. This type of journaling helps recover lost or E    corrupted files. After-image recovery restores the contents of the >    file from the point of the latest backup copy of that file.  C o  Before-image (BI) journaling allows you to undo a series of mod- D    ifications to a file. This type of journaling returns the file toE    a previous known state. This is useful when a file is updated with     erroneous data.  C                                                          April 2001        F o  Recovery unit (RU) journaling helps maintain transaction integrity,E    where a transaction consists of a group of related operations that D    must be atomic. That is, either all of the operations complete inC    their entirety, or none of the operations complete. This type of F    journaling helps prevent data from becoming inconsistent due to the)    incomplete execution of a transaction.   C Journaling is applied on a file-by-file basis. A file can be marked I for AI, BI, or RU journaling, or any combination of these methods. Within G a given application, any combination of journaling methods can be used.   D RMS Journaling for OpenVMS stores the information necessary for dataD recovery in files known as journals. Multiple files can use the same journal.  ' RMS Recovery Unit Journaling and DECdtm  Transactions  F Transactions are defined and managed using the DECdtm transaction ser-D vices available within OpenVMS. An RMS recovery unit is a set of RMSE record operations, performed in the context of a single process, that C is part of a transaction coordinated by DECdtm services. RMS recov- F ery units are started automatically by RMS, and RMS recovery units areC committed or aborted along with the transaction of which they are a  part.   D RMS Journaling for OpenVMS functions as a resource manager in trans-E actions that use DECdtm services. DECdtm services are implemented us- C ing a two-phase commit protocol as described in the OpenVMS Operat- C ing System Software Product Description (SPD 25.01.xx). RU journal- > ing supports both a one-phase and a two-phase commit protocol.  C Remote RMS files (files accessed via the DAP/FAL protocol) that are F marked for RU journaling can be modified within a transaction and willH be included in the atomic unit of work defined by the transaction. Also,C the modifications made to RMS files marked for RU journaling can be E combined with modifications made using any resource manager that sup- 7 ports DECdtm services into a single atomic transaction.     "                                  2       H The Recovery Unit Facility (RUF) services have been superseded by DECdtmF services. However, the RUF services are still supported and are trans-G parently emulated using the DECdtm services. Existing applications that C were written using the RUF services continue to work without recom-  pilation or relinking.   Supported File Organizations  D All RMS file organizations are supported by RMS Journaling for Open-E VMS. Any sequential, relative, or Prolog 3 indexed file can use jour- 2 naling. However, the following restrictions apply:  E o  Prolog 1 and Prolog 2 indexed files are not supported by RMS Jour-     naling for OpenVMS.  ? o  Sequential files have a maximum record size of 32,667 bytes.   F o  Files marked for RU journaling cannot be modified with the DCL com-    mand WRITE.  E o  Stream files cannot be modified in shared mode in a recovery unit.   D o  Sequential files having VFC record format do not allow shared ac-    cess for RU journaling.  D When using RU journaling with shared, fixed-length sequential files,G any abort processing overwrites records added to the recovery unit with C zero bytes (null characters). This occurs because the record cannot  be deleted from the file.   D All files that are marked for journaling must reside on Files-11 On-E Disk Structure 2 (ODS-2) disks. All journals must also reside on ODS- C 2 disks. Compaq recommends that journals used for AI journaling re- F side on a disk volume that is different from the disk volume where theD data file that uses the journal resides. Journaling across a network% or to a tape device is not supported.    Marking Files for Journaling    "                                  3       D RMS Journaling for OpenVMS is enabled on a file-by-file basis. FilesD marked for AI, BI, and RU journaling are enabled by using qualifiersF to the DCL command SET FILE. You can use any combination of qualifiersB with a particular SET FILE command or series of SET FILE commands.  D The most recent SET FILE command for a given file overrides all pre-& vious SET FILE commands for that file.  C Successful marking of an RMS file for journaling requires exclusive C access to the file specified in the SET FILE command. Exclusive ac- C cess means the RMS file being marked for journaling must be closed; C that is, application programs accessing that file must be shut down : before the file can be successfully marked for journaling.  C No modifications to application programs are required for long-term F (AI or BI) journaling. Once a file has been marked for long-term jour-D naling, journal information will be written to the journal each timeE the file is modified. You must enter the SET FILE command to mark the E file for journaling before opening the file. All modifications to the E file are recorded in the journal until the file is unmarked for jour-  naling.   E Modifications to application programs are required for RU journaling. D At a minimum, the program must specify the start and end of a recov-F ery unit, using DECdtm transactions or RU system services. When a fileF is marked for recovery unit journaling, all modifications to that file7 made by the application must be within a recovery unit.    Journal File Maintenance  E AI and BI journals require periodic maintenance. Because journals can F expand indefinitely, and a journal must reside on a single volume set,D occasional remarking of a file for journaling and all of the associ-C ated operations is required. This implies that applications access- F ing RMS files marked for AI or BI journaling, or both, must be stopped0 periodically for journal maintenance operations.  & Recovering Data - Long-Term Journaling    "                                  4       D In the case of long-term (either AI or BI) journaling, data recoveryE is done using the RMS Recovery utility. Recovery is on a file-by-file E basis and must be explicitly requested; it is not done automatically. D The RMS Recovery utility is invoked at DCL level to either roll for-D ward or roll back changes to the file. The Recovery utility requiresC exclusive access to the file being recovered. Changes can be rolled > forward or rolled backward until a time specified by the user.  * Recovering Data - Recovery Unit Journaling  E No user intervention is required to roll back a recovery unit that is D incomplete. The rollback of an incomplete transaction is started andC completed automatically the next time a user attempts to access the  file.   # Interaction with the Backup Utility   C To recover data using AI journaling, a backup copy of the file must F be available. This copy must be made with the Backup utility (BACKUP);H a copy of the file made with the COPY or CONVERT command cannot be used.I The backup copy of the file must be made after you enter the SET FILE/AI_ G JOURNAL command but before opening the file for update. BACKUP requires F exclusive access to files being backed up. No user or application pro-6 gram can access the file until the backup is finished.  F Compaq recommends the use of BACKUP/RECORD. If the file is then rolledD forward, the modifications that have been made since the most recent backup are applied.   H If a backup copy of a file is rolled forward with the RMS Recovery util-E ity, you must remark the file for AI journaling with the SET FILE/AI_ E JOURNAL command. You must make a backup copy of that file after mark- D ing it for AI journaling and before application updates are allowed.  E A backup copy of the file must be remarked for journaling if it is to & be used in place of the original file.  - Interaction with Volume Shadowing for OpenVMS     "                                  5       E Volume Shadowing for OpenVMS can be used in conjunction with AI jour- C naling. AI journaling helps recover data in the following cases not * addressed by Volume Shadowing for OpenVMS:  2 o  Mistaken deletion of a file by a system user or    operator   ) o  Corruption of the file system pointers   C o  RMS file corruption due to a software error or incomplete bucket &    write operations to an indexed file  + Failures Not Addressed by RMS Recovery Unit 
 Journaling  F RU journaling alone does not provide recovery when a multiblock bucketE write operation to an indexed file is in progress, leaving the bucket E in the indexed file in a corrupt state. Use AI journaling in conjunc- C tion with RU journaling to recover from the following failed multi-  block bucket write operations:   C o  Failure of the VAX or Alpha host during a multiblock write oper- H    ation, such as a system failure, halt, power failure, or system shut-    down.  C o  Permanent loss of path to the disk during a multiblock write op-     eration.   E o  Cancellation of a multiblock write operation in progress. This op- D    eration is possible only with disks that use the DUDRIVER or thatE    access a disk drive through the MSCP server. Other disk drives ig- 5    nore the cancellation of I/O and are not affected.    HARDWARE REQUIREMENTS   G Refer to the OpenVMS Operating System Software Product Description (SPD = 25.01.xx) for hardware requirements and supported processors.     "                                  6        OpenVMS CLUSTER ENVIRONMENT   E This layered product is fully supported without restrictions when in- E stalled on any valid and licensed OpenVMS Cluster* configuration. The C Hardware Requirements section of this product's SPD and the OpenVMS E Operating System Software Product Description (SPD 25.01.xx) list any * special hardware required by this product.  D *  OpenVMS Cluster configurations are fully described in the OpenVMSF    Cluster Software Product Description (SPD 29.78.xx) and include CI,/    Ethernet, DSSI, FDDI, and MC configurations.    SOFTWARE REQUIREMENTS   F RMS Journaling for OpenVMS Version 7.3 is an OpenVMS System Integrated* Product that requires OpenVMS Version 7.3.  G For additional information, refer to the OpenVMS Operating System Soft- ( ware Product Description (SPD 25.01.xx).   OpenVMS Tailoring   D For OpenVMS Version 7.3, the following OpenVMS class is required for0 full features of this System Integrated Product:      OpenVMS Required Save Set  F For more information about OpenVMS classes and tailoring, refer to theE OpenVMS Operating System Software Product Description (SPD 25.01.xx).    GROWTH CONSIDERATIONS   E The minimum hardware and software requirements for any future version C of this product may be different from the requirements for the cur- 
 rent version.           "                                  7        DISTRIBUTION AND INSTALLATION   C RMS Journaling for OpenVMS Version 7.3 is a System Integrated Prod- E uct that is distributed and installed with the OpenVMS operating sys-  tem Version 7.3.   ORDERING INFORMATION  " For RMS Journaling on OpenVMS VAX:   Software Licenses: QL-VDVA*-**# Software Documentation: QA-VDVAA-GZ & Software Product Services: QT-VDVA*-**  $ For RMS Journaling on OpenVMS Alpha:   Software Licenses: QL-0VHA*-**# Software Documentation: QA-VDVAA-GZ & Software Product Services: QT-0VHA*-**  F *  Denotes variant fields. For additional information on available li-E    censes, services, and media, contact your Compaq support represen- 
    tative.   SOFTWARE LICENSING  C This software is furnished under the licensing provisions of Compaq E Computer Corporation's Standard Terms and Conditions. For more infor- F mation about the licensing terms and policies, contact your local Com- paq office.    License Management Facility   C This System Integrated Product supports the OpenVMS License Manage-  ment Facility.  C License units for this product are sold on a capacity (per CPU) ba-  sis.    "                                  8       D For more information about the License Management Facility, refer toH the OpenVMS Operating System Software Product Description (SPD 25.01.xx)D or the OpenVMS License Management Utility Manual in the OpenVMS doc- umentation set.   E For more information about licensing terms and policies, contact your  local Compaq office.   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 Warranty for this software product is provided by Compaq with the pur-F chase of a license for the product as defined in the Software Warranty Addendum of this SPD.   E The previous information is valid at the time of this release. Please E contact your local Compaq office for the most up-to-date information.   "  2001 Compaq Computer Corporation  E AlphaServer, Compaq, StorageWorks, VAX, VMS, and the Compaq logo Reg- , istered in U.S. Patent and Trademark Office.  E OpenVMS is a trademark of Compaq Information Technologies Group, L.P. ) in the United States and other countries.   C Microsoft, Windows, and Windows NT are trademarks of Microsoft Cor- 2 poration in the United States and other countries.  E Motif is a trademark of The Open Group in the United States and other 
 countries.  G All other product names mentioned herein may be the trademarks of their  respective companies.     "                                  9       F Confidential computer software. Valid license from Compaq required forG possession, use or copying. Consistent with FAR 12.211 and 12.212, Com- E mercial Computer Software, Computer Software Documentation, and Tech- C nical Data for Commercial Items are licensed to the U.S. Government + under vendor's standard commercial license.   E Compaq shall not be liable for technical or editorial errors or omis- D sions contained herein. The information in this document is providedC "as is" without warranty of any kind and is subject to change with- C out notice. The warranties for Compaq products are set forth in the E express limited warranty statements accompanying such products. Noth- F ing herein should be construed as constituting an additional warranty.                                                        "                                 10                                                                                       "                                 11                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              