Software Product Description ___________________________________________________________________ PRODUCT NAME: HP RMS Journaling for OpenVMS SPD 27.58.14 Note: This is the Software Product Description (SPD) for the follow- ing products: o HP RMS Journaling for OpenVMS for Integrity servers, Version 8.2 o HP RMS Journaling for OpenVMS Alpha, Version 8.2 o HP RMS Journaling for OpenVMS VAX Version 7.3 Except where specifically noted, the features described in this SPD apply to all three products. The license and part number information is architecture specific. Please refer to the Ordering Information sec- tion of this SPD for further details. DESCRIPTION RMS Journaling for OpenVMS helps maintain the data integrity of Open- VMS RMS files and protects this file data from becoming lost or in- consistent due to various failure scenarios. RMS Journaling for OpenVMS provides the following three methods of jour- naling: o After-image (AI) journaling allows you to redo a series of modi- fications to a file. This type of journaling helps recover lost or corrupted files. After-image recovery restores the contents of the file from the point of the latest backup copy of that file. o Before-image (BI) journaling allows you to undo a series of mod- ifications to a file. This type of journaling returns the file to a previous known state. This is useful when a file is updated with erroneous data. January 2005 o Recovery unit (RU) journaling helps maintain transaction integrity, where a transaction consists of a group of related operations that must be atomic. That is, either all of the operations complete in their entirety, or none of the operations complete. This type of journaling helps prevent data from becoming inconsistent due to the incomplete execution of a transaction. Journaling is applied on a file-by-file basis. A file can be marked for AI, BI, or RU journaling, or any combination of these methods. Within a given application, any combination of journaling methods can be used. RMS Journaling for OpenVMS stores the information necessary for data recovery in files known as journals. Multiple files can use the same journal. RMS Recovery Unit Journaling and DECdtm Transactions Transactions are defined and managed using the DECdtm transaction ser- vices available within OpenVMS. An RMS recovery unit is a set of RMS record operations, performed in the context of a single process, that is part of a transaction coordinated by DECdtm services. RMS recov- ery units are started automatically by RMS, and RMS recovery units are committed or aborted along with the transaction of which they are a part. RMS Journaling for OpenVMS functions as a resource manager in trans- actions that use DECdtm services. DECdtm services are implemented us- ing a two-phase commit protocol. RU journaling supports both a one- phase and a two-phase commit protocol. Remote RMS files (files accessed via the DAP/FAL protocol) that are marked for RU journaling can be modified within a transaction and will be included in the atomic unit of work defined by the transaction. Also, the modifications made to RMS files marked for RU journaling can be combined with modifications made using any resource manager that sup- ports DECdtm services into a single atomic transaction. 2 The Recovery Unit Facility (RUF) services have been superseded by DECdtm services. However, the RUF services are still supported and are trans- parently emulated using the DECdtm services. Existing applications that were written using the RUF services continue to work without recom- pilation or relinking. Supported File Organizations All RMS file organizations are supported by RMS Journaling for Open- VMS. Any sequential, relative, or Prolog 3 indexed file can use jour- naling. However, the following restrictions apply: 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. o Files marked for RU journaling cannot be modified with the DCL com- mand WRITE. o Stream files cannot be modified in shared mode in a recovery unit. o Sequential files having VFC record format do not allow shared ac- cess for RU journaling. When using RU journaling with shared, fixed-length sequential files, any abort processing overwrites records added to the recovery unit with zero bytes (null characters). This occurs because the record cannot be deleted from the file. All files that are marked for journaling must reside on Files-11 On- Disk Structures 2 (ODS-2) and 5 (ODS-5) disks. All journals must also reside on ODS-2 or ODS-5 disks. It is recommended that journals used for AI journaling reside on a disk volume that is different from the disk volume where the data file that uses the journal resides. Jour- naling across a network or to a tape device is not supported. Marking Files for Journaling 3 RMS Journaling for OpenVMS is enabled on a file-by-file basis. Files marked for AI, BI, and RU journaling are enabled by using qualifiers to the DCL command SET FILE. You can use any combination of qualifiers with a particular SET FILE command or series of SET FILE commands. The most recent SET FILE command for a given file overrides all pre- vious SET FILE commands for that file. Successful marking of an RMS file for journaling requires exclusive access to the file specified in the SET FILE command. Exclusive ac- cess means the RMS file being marked for journaling must be closed; that is, application programs accessing that file must be shut down before the file can be successfully marked for journaling. No modifications to application programs are required for long-term (AI or BI) journaling. Once a file has been marked for long-term jour- naling, journal information will be written to the journal each time the file is modified. You must enter the SET FILE command to mark the file for journaling before opening the file. All modifications to the file are recorded in the journal until the file is unmarked for jour- naling. Modifications to application programs are required for RU journaling. At a minimum, the program must specify the start and end of a recov- ery unit, using DECdtm transactions or RU system services. When a file is marked for recovery unit journaling, all modifications to that file made by the application must be within a recovery unit. Journal File Maintenance AI and BI journals require periodic maintenance. Because journals can expand indefinitely, and a journal must reside on a single volume set, occasional remarking of a file for journaling and all of the associ- ated operations is required. This implies that applications access- ing RMS files marked for AI or BI journaling, or both, must be stopped periodically for journal maintenance operations. Recovering Data - Long-Term Journaling 4 In the case of long-term (either AI or BI) journaling, data recovery is done using the RMS Recovery utility. Recovery is on a file-by-file basis and must be explicitly requested; it is not done automatically. The RMS Recovery utility is invoked at DCL level to either roll for- ward or roll back changes to the file. The Recovery utility requires 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 No user intervention is required to roll back a recovery unit that is incomplete. The rollback of an incomplete transaction is started and completed automatically the next time a user attempts to access the file. Interaction with the Backup Utility To recover data using AI journaling, a backup copy of the file must be available. This copy must be made with the Backup utility (BACKUP); a copy of the file made with the COPY or CONVERT command cannot be used. The backup copy of the file must be made after you enter the SET FILE/AI_ JOURNAL command but before opening the file for update. BACKUP requires exclusive access to files being backed up. No user or application pro- gram can access the file until the backup is finished. HP recommends the use of BACKUP/RECORD. If the file is then rolled for- ward, the modifications that have been made since the most recent backup are applied. If a backup copy of a file is rolled forward with the RMS Recovery util- ity, you must remark the file for AI journaling with the SET FILE/AI_ JOURNAL command. You must make a backup copy of that file after mark- ing it for AI journaling and before application updates are allowed. 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 Volume Shadowing for OpenVMS can be used in conjunction with AI jour- naling. AI journaling helps recover data in the following cases not addressed by Volume Shadowing for OpenVMS: o Mistaken deletion of a file by a system user or operator o Corruption of the file system pointers o RMS file corruption due to a software error or incomplete bucket write operations to an indexed file Failures Not Addressed by RMS AI Journaling In the case of either a process deletion or system failure, an update can be written to the AI journal file, but not make it to the data file. If only AI journaling is in use, the data file and journal are not au- tomatically made consistent. If additional updates are made to the data file and are recorded in the AI journal, a subsequent manual roll for- ward operation could produce an inconsistent data file. If you use RMS RU journaling in combination with AI journaling, the automatic transaction recovery restores consistency between the AI jour- nal and the data file. Under some circumstances, an application that uses only AI journal- ing can take proactive measures to guard against data inconsistencies after process deletions or system failures. For example, a manual roll forward of AI-journaled files ensures consistency after a system fail- ure involving either an unshared AI application (single accessor) or a shared AI application executing on a standalone system. However, in a shared AI application, there may be nothing to prevent further operations being executed against a data file that is out of synchronization with the AI journal file after a process deletion or system failure in a cluster. Under these circumstances, consistency among the data file(s) and the AI journal file can be provided by us- ing a combination of AI and RU journaling. Failures Not Addressed by RMS Recovery Unit Journaling 6 RU journaling alone does not provide recovery when a multiblock bucket write operation to an indexed file is in progress, leaving the bucket in the indexed file in a corrupt state. Use AI journaling in conjunc- tion with RU journaling to recover from the following failed multi- block bucket write operations: o Failure of the I64, Alpha, or VAX host during a multiblock write operation, such as a system failure, halt, power failure, or sys- tem shutdown. o Permanent loss of path to the disk during a multiblock write op- eration. o Cancellation of a multiblock write operation in progress. This op- eration is possible only with disks that use the DUDRIVER or that access a disk drive through the MSCP server. Other disk drives ig- nore the cancellation of I/O and are not affected. HARDWARE REQUIREMENTS Refer to the HP OpenVMS Operating System for Alpha Version 7.3-1 and 7.3-2 and VAX Version 7.3 Software Product Description (SPD 25.01.xx) or the HP OpenVMS for Integrity Servers and HP OpenVMS Alpha Version 8.2 Operating Systems Software Product Description (SPD 82.35.xx), and the OpenVMS Cluster Software Software Product Description (SPD 29.78.xx) for hardware requirements and supported processors. OpenVMS CLUSTER ENVIRONMENT This layered product is fully supported without restrictions when in- stalled on any valid and licensed OpenVMS Cluster* configuration. The Hardware Requirements section of this product's SPD and the HP Open- VMS Operating System for Alpha Version 7.3-1 and 7.3-2 and VAX Ver- sion 7.3 Software Product Description (SPD 25.01.xx) or the HP Open- VMS for Integrity Servers and HP OpenVMS Alpha Version 8.2 Operating Systems Software Product Description (SPD 82.35.xx), and the OpenVMS Cluster Software Software Product Description (SPD 29.78.xx) list any special hardware required by this product. 7 * OpenVMS Cluster configurations are fully described in the HP Open- VMS Cluster Software Product Description (SPD 29.78.xx) and include CI, Ethernet, FDDI, Fibre Channel, and MC configurations. SOFTWARE REQUIREMENTS RMS Journaling for OpenVMS is an OpenVMS System Integrated Product that requires the corresponding OpenVMS operating system version. For further information, refer to the HP OpenVMS Operating System for Alpha Version 7.3-1 and 7.3-2, and VAX Version 7.3 Software Product Description (SPD 25.01.xx) or the HP OpenVMS for Integrity Servers and HP OpenVMS Alpha Version 8.2 Operating Systems Software Product De- scription (SPD 82.35.xx), and the OpenVMS Cluster Software Software Product Description (SPD 29.78.xx). OpenVMS Tailoring For OpenVMS, the following OpenVMS class is required for full features of this System Integrated Product: OpenVMS Required Save Set For more information about OpenVMS classes and tailoring, refer to the HP OpenVMS Operating System for Alpha Version 7.3-1 and 7.3-2, and VAX Version 7.3 Software Product Description (SPD 25.01.xx) or the HP Open- VMS for Integrity Servers and HP OpenVMS Alpha Version 8.2 Operating Systems Software Product Description (SPD 82.35.xx) GROWTH CONSIDERATIONS The minimum hardware and software requirements for any future version of this product may be different from the requirements for the cur- rent version. 8 DISTRIBUTION AND INSTALLATION RMS Journaling for OpenVMS is a System Integrated Product that is dis- tributed and installed with the OpenVMS operating system. 9 ORDERING INFORMATION For RMS Journaling on OpenVMS I64: Software Licenses: Per Processor: BA409AC The RMS Journaling on OpenVMS I64 license is also included with the Enterprise Operating Environment (EOE) license bundle. Please refer to the HP Operating Environments for OpenVMS Industry Standard 64 for Integrity servers Software Product Description (SPD 82.34.xx) for or- dering information. Software Media: Foundation Operating Environment Media, BA322AA or Enterprise Operating Environment Media, BA323AA or Mission Critical Operating Environment Media, BA324AA For RMS Journaling on OpenVMS Alpha: Software Licenses: QL-0VHA*-** Software Documentation: QA-VDVAA-GZ Software Product Services: QT-0VHA*-** For RMS Journaling on OpenVMS VAX: Software Licenses: QL-VDVA*-** Software Documentation: QA-VDVAA-GZ Software Product Services: QT-VDVA*-** * Denotes variant fields. For additional information on available li- censes, services, and media, contact your HP support representa- tive. 10 SOFTWARE LICENSING This software is furnished under the licensing provisions of Hewlett- Packard's Standard Terms and Conditions. License Management Facility This System Integrated Product supports the OpenVMS License Manage- ment Facility. License units for this product are sold on a capacity (per CPU) ba- sis. For more information about the License Management Facility, refer to the HP OpenVMS Operating System for Alpha Version 7.3-1 and 7.3-2, and VAX Version 7.3 Software Product Description (SPD 25.01.xx) or the HP OpenVMS for Integrity Servers and HP OpenVMS Alpha Version 8.2 Oper- ating Systems Software Product Description (SPD 82.35.xx) or the (VMS_LICENSE) in the OpenVMS documentation set. 11 For more information regarding licensing terms and policies, contact your local HP sales office, or find HP software licensing information on the World Wide Web at: http://h18000.www1.hp.com/products/software/ info/terms/swl_sld.html SOFTWARE PRODUCT SERVICES A variety of service options are available from HP. For more infor- mation, contact your local HP account representative or distributor. Information is also available from http://www.hp.com/hps/software. SOFTWARE WARRANTY This software product is provided by HP with a 90-day conformance war- ranty in accordance with the HP warranty terms applicable to the li- cense purchase. © 2005 Hewlett-Packard Development Company, L.P. Confidential computer software. Valid license from HP required for pos- session, use or copying. Consistent with FAR 12.211 and 12.212, Com- mercial Computer Software, Computer Software Documentation, and Tech- nical Data for Commercial Items are licensed to the U.S. Government under vendor's standard commercial license. The information contained herein is subject to change without notice. The only warranties for HP products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional war- ranty. HP shall not be liable for technical or editorial errors or omis- sions contained herein. 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