Removing a storage system from an active Global Mirror configuration running on a Copy Services Manager session

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During hardware migration that involves equipment that is running Copy Services Manager sessions, there is a manual process to remove a storage system from an active Global Mirror configuration.

About this task

When DS8000 sets up a Global Mirror relationship, it can span multiple source (H1) storage systems and creates a master/subordinate topology. The master source storage system coordinates the consistency group formation with the other subordinate source storage systems.

When you remove a storage system from a Global Mirror configuration, steps need to be taken to update the master/subordinate topology on the DS8000.

To modify the topology on the hardware, consistency group formation needs to be stopped. The Copy Services Manager session does not automatically stop consistency group formation when removing the last copy set from the storage system that is being removed.

Before removing the storage system completely from the environment, the following steps should be performed when consistency group formation can be temporarily stopped.

Complete these steps to remove a storage system from an active Global Mirror configuration running on a Copy Services Manager session:
Note: Do not attempt this manual process of removing a storage system during a highly active or sensitive time frame in your storage environment.

Procedure

  1. Add in new copy sets to replace the old source storage system, and populate the copy sets with the old source storage system data with a product such as TDMF.
  2. After all data is migrated and you are ready to remove the source storage system from the environment, remove the copy sets from the Copy Services Manager session.
  3. Suspend the Global Mirror session or the Global Mirror leg of a 3 or 4 site session.
    Note: If the Suspend operation fails, you need to issue the Stop command to reach a suspended Global Mirror leg. If a Stop is processed, it will remove the Global Mirror Master configuration from the hardware.
  4. Issue a Recover to the Global Mirror session, or Failover to the Global Mirror target in a 3 or 4 site multi-target session.
    Note: For Metro Global Mirror with Practice (MGMP) sessions, you cannot issue the Recover H3 command. You need to ensure that you issue the Stop command while the Session is in Suspending Hx-H3 state.
  5. Restart the Global Mirror session or the Global Mirror leg of a 3 or 4 site session.
    Note: During the restart, Copy Services Manager detects that the old source storage system is no longer in the session, and builds the new master/subordinate topology.
  6. Remove the connection for the old source storage system.