Returning Global Mirror to the primary site in an unplanned outage

If a Global Mirror session is not running from the recovery site to the primary site, go to step 4.

Figure 1. Returning Global Mirror to Primary Site in an Unplanned Outage
Failback in a Global Mirror Environment
  1. Quiesce applications at the recovery site to reduce the risk of data loss.
  2. Allow two consistency group formations to complete. Use the RQUERY command to confirm.
  3. Terminate the Global Mirror session using the RSESSION command specifying the STOP ACTION.
    1. If the master does not stop, reissue the command. If the master still does not stop, reissue RSESSION specifying the MASTER YES and FORCE parameters.
    2. Issue RQUERY to determine if any storage control subordinates are still running.
    3. Issue RSESSION to each subordinate storage control still running, specifying the MASTER NO parameter.
  4. Verify that paths are still established from the primary site to the recovery site. Issue PPRC Establish Paths commands if necessary.
  5. Issue the PPRC Establish Pair command to the A volume as the DEVN, specifying the FAILOVER ACTION with the original PRIMARY and SECONDARY parameters. The A volumes now become suspended primaries with change recording active and write inhibit removed.
  6. Restart applications at the primary site.
  7. Issue the PPRC Establish Pair command to the A volume as the DEVN, specifying the FAILBACK ACTION with the original PRIMARY and SECONDARY parameters to resynchronize the A and B volumes in the original recovery configuration.
  8. If a Global Mirror session from the recovery site to the primary site was started, terminate the FlashCopy® relationship at the primary site with the FlashCopy Withdraw command.
  9. Start a new the Flashcopy relationship between B and C volumes at the recovery site, using the FlashCopy Establish command and specifying ASYNC with the MODE parameter.
  10. If necessary, issue the RSESSION command at the primary site, with the DEFINE ACTION to specify the topology of the new Global Mirror session.
  11. If necessary, issue the PPRC Establish Paths command at the primary site to provide a path for data flow between the Master and storage control subordinates at the recovery site.
  12. If necessary, use the RVOLUME command at the primary site, specifying the JOIN ACTION to populate the session with primary volumes at the recovery site.
  13. Issue RSESSION START to the Master at the primary site to begin the Global Mirror session.
Parent topic: Failover/failback for a Global Mirror session