Disaster recovery from the primary site (PPRC cascade)

True Copy for Mainframe User Guide for VSP One Block 85
Version
10.5.x
File Size
2745 KB
Audience
anonymous
Part Number
MK-26VSP1B036-02
ft:lastEdition
2026-06-23

Operation can be continued by using the volume at the intermediate site if the primary site fails in a PPRC cascade configuration. Switch operations from the primary site to the intermediate site first if the primary site fails. The following procedure assumes that site B is the primary site, site A is the intermediate site, and site C is the secondary site in a PPRC cascade configuration. The procedure describes how to resume business at site A and then restore the duplex configuration.



  1. At site A, note the TCz pair status and fence level of the volume that is paired with the TCz volume at site B.
  2. At site A, confirm data in the volume is guaranteed by the pair status and the fence level. See Checking S-VOL consistency with the P-VOL.
    For pairs whose P-VOL fence level is set to never, further analysis is required to determine the volume consistency. This can be determined by using sense information transferred by host failover or by comparing the contents of the volume with other files that are confirmed to be consistent (for example, database log files). The volume should be recovered using the files that are confirmed to be consistent.
  3. Recover files if necessary.
  4. At site B, perform the Freeze command on the pair at site A.
  5. At site B, perform the Run command on the pair at site A.
  6. At site A, perform the Failover command on the TCz volume that is paired with TCz volume at site B.


  7. At site A, perform the Failback command on the TCz volume that is paired with TCz volume at site B.
  8. Confirm that all recovery operations are completed at site A before varying the TCz volumes paired with site B online.
    If IPL in the secondary host is required, perform the following procedures.
    1. Contact maintenance personnel and complete remote copy SIMs before performing OS IPL.
    2. Perform IPL in the secondary host.
    3. Vary the volume online after IPL is completed.
      Perform this step when the volume is not varied online automatically.
  9. Resume operations at site A.
    If you want to duplicate data before starting operations, perform the following steps (a) and (b) before resuming operations at site A.
    1. At site A, perform Resync on the TCz volume that is paired with site C because the TCz volume is in Suspend status.


    2. Confirm that the TCz pair status between site A and site C has changed to Duplex.
  10. At site A, perform Resync to the TCz volume that is paired with site B after site B is recovered from the failure.
    This operation changes the configuration to PPRC multi-target with site A as the primary site.



After you have completed this procedure, site A becomes the primary site in the PPRC multi-target configuration.

To change the PPRC multi-target configuration back to the original PPRC cascade configuration, see Configuring PPRC cascade.