IBM SG24-5360-00 manual Peer-to-Peer Remote Copy

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Chapter 5. Peer-to-Peer Remote Copy

In this chapter we describe the VSE/ESA support for the RVA and the PPRC.

As part of the continuing effort to meet customer requirements for 24-hour 7-day availability, the RVA Model T82 provides remote copy for disaster and critical volume protection. PPRC is supported by OS/390, VSE/ESA, and VM/ESA. PPRC complements the existing availability functions of the RVA, such as the dual power systems, nonvolatile storage (NVS), and nondisruptive installation and repair.

PPRC standardizes and streamlines today′s disaster recovery data backup capabilities by providing data-type independent remote copy. The implementation provides a choice based on business requirements such as performance needs, data synchrony criteria, system resource considerations, operational control requirements, and recovery distance requirements.

PPRC provides an RVA synchronous data copying capability for protection against loss of access to data in the event of an outage at the primary site. Updates are sent from the primary RVA directly to the recovery RVA in a cache to cache communication through dedicated ESCON links between the two RVAs. The RVA can be located up to 43 km (26.7 mi) from the host. The primary and secondary volumes must be of the same track geometry.

Figure 19 shows two host systems with an RVA attached to each. The two RVAs are attached on at least one ESCON path. ESCON Directors can be used to extend the distance between the two hosts up to 43 km. The second host is optional if PPRC is being used to migrate data from one RVA to a second within the same data center.

Figure 19. Peer-to-Peer Remote Copy

Both RVAs can treat writes as DASD fast write (DFW) operations. The primary RVA write is handled normally, and it is processed as a cache hit whenever possible; the write to the secondary subsystem is always treated as a write hit. This capability, and the inherent performance capabilities of the RVA, help to mitigate the unavoidable performance impacts of writing the data to both RVAs before signaling the operation as complete to the primary host application.

© Copyright IBM Corp. 1999

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Contents International Technical Support Organization Page International Technical Support Organization First Edition January Contents Peer-to-Peer Remote Copy Itso Redbook Evaluation Contents Vi Ramac Virtual Array, Peer-to Peer Remote VSE/ESA Team That Wrote This Redbook PrefaceYour comments are important to us Comments WelcomeLog Structured File What Is an IBM Ramac Virtual Array?IBM Ramac Virtual Array Overview of RVA and the Virtual Disk Architecture− Functional track table Data Compression and CompactionWhat Is SnapShot? What Is IXFP/SnapShot for VSE/ESA?VSE/ESA Support for the RVA Deleted Data Space Release What Is IXFP?Reporting Functions What Is Peer-to-Peer Remote Copy?Ramac Virtual Array, Peer-to Peer Remote VSE/ESA RVA Simplifies Your Storage Management RVA Benefits for VSE/ESADisk Capacity Ixfp AdministrationBatch Window Improvement IXFP/SnapShot for VSE/ESA Ramac Virtual ArrayRVA Data Availability Application DevelopmentHardware Pprc SnapShotRamac Virtual Array, Peer-to Peer Remote VSE/ESA Prerequisites VSE/ESA Support for the RVA1 VSE/ESA Input/Output Configuration Program VolumesHost Connection Exec Volume Minimal InitPartial Disk Minimal Init AssgnRamac Virtual Array, Peer-to Peer Remote VSE/ESA System VSE/ESA User Time IXFP/SnapShot for VSE/ESASample Batch Job to Invoke Ixfp Report Function DTRIATTN,PARM=′ Ixfp REPORT′IXFP/SnapShot for VSE/ESA Defined DetailPhys AR 0015 CUU DEFIxfp Snap Full VolumeVSE/VSAM Reply ′ YES′ to ProceedRange of Cylinders Non-VSAM File Expired Files Ixfp DDSR,PATEV3 Total VolumeIxfp DDSR,PATEV30000-0999,NOPROMPT Ixfp DDSR,PATEV3DSN=′ test.data.3′ , Noprompt Specified FileIxfp REPORT,80E,80F Ixfp REPORT,80E Ixfp REPORT,80FIxfp Report Device Detail Report Sample Output of Ixfp Report CommandRamac Virtual Array, Peer-to Peer Remote VSE/ESA Subsystem Summary Report Device Summary ReportRamac Virtual Array, Peer-to Peer Remote VSE/ESA Peer-to-Peer Remote Copy Peer-to-Peer Remote CopyPprc Data Flow Pprc and VSE/ESA Software RequirementsInvoking peer-to-peer remote copy Pprc Hardware RequirementsSecondary Devices of a Pprc Pair Examples of Pprcopy CommandsSnapShot Considerations Primary Devices of a Pprc PairRecovering from a Primary Site Failure Setting Up Pprc Paths and PairsDeleting Pprc Pairs and Paths Recovering from a Secondary Site FailurePhysical Connections to the RVA Determining the Channel Connection Address Determining the Logical Control Unit Number for RVARamac Virtual Array, Peer-to Peer Remote VSE/ESA Functional Device Configuration Appendix A. RVA Functional Device ConfigurationFunctional Device Configuration Screen CD23 Snap Command Appendix B. Ixfp Command ExamplesSyntax Ramac Virtual Array, Peer-to Peer Remote VSE/ESA Noprompt Using SnapShot to Copy One Volume to AnotherDEFINED-CAPACITY AR 0015 CapacityTest Prod Overall Test Prod Using SnapShot to Copy Files with Relocation Using SnapShot to Copy a File from One Volume to AnotherIXFP20I Snap Function Completed AT Other Uses of SnapShotSyntax of Ixfp Ddsr Command Details Ddsr CommandUsing Ddsr to Delete the Contents of a Volume Using Ddsr to Delete a Single Data SetReport Using Ddsr to Delete the Free Space on an RVAAR+0015 IXFP29D Ddsr for For Deletion Report Command Device Detail Report FUNC. Capacity MB Reporting on the Capacity of a Single VolumeReporting on the Capacity of Multiple Volumes Reporting on the Capacity of the RVA SubsystemJOB WCWTEST1 IXFP/SnapShot Setup Job StreamsExec DTRIATTN,PARM=′ Ixfp REPORT′ Ready Ixfp DDSR,80F BG 0000 // JOB InitdiskBG 0000 1A86I Following Assignments are Released Ixfp DDSR,80E$$DITTO BLKFACTOR=1 EOJ 50.83 47.86 AR 0015 1I40I Ready$$DITTO BLKFACTOR=1 $$DITTO EOJ 726532.208 MB 117880.209 MB 57754.953 MB Appendix C. VSE/VSAM Considerations Backing up Vsam Volumes Appendix C. VSE/VSAM Considerations Ramac Virtual Array, Peer-to Peer Remote VSE/ESA Appendix D. Iocds Example Ramac Virtual Array, Peer-to Peer Remote VSE/ESA Appendix E. Special Notices Following terms are trademarks of other companies Other Publications Appendix F. Related PublicationsInternational Technical Support Organization Publications Redbooks on CD-ROMsRamac Virtual Array, Peer-to Peer Remote VSE/ESA ∙ E-mail Orders How to Get Itso RedbooksPlease send me the following IBM Redbook Fax Order FormSee CKD IndexPprc distance Please answer the following questions Itso Redbook EvaluationSG24-5360-00