Planned outage of production (H1 MM source) with production move to remote (H3 GM target)

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In this scenario, there is a planned outage for Site 1 (H1). Site 2, however, does not have the resources to run production, so production will be moved to Site 3 during the outage at Site 1. When the outage is complete, production can then be moved back to Site 1 and resume the full three-site configuration. Procedures are shown for both the multi-target Metro Mirror - Global Mirror session type as well as the Metro Global Mirror session type.

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Follow these steps to carry out this scenario.

Procedure for Multi-Target Metro Mirror - Global Mirror session type

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Procedure

  1. Start H1->H2 H1->H3

    Issue this command to begin multi-target replication on your system when the production I/O is running on H1. Once the session is in a Prepared state, both sites 2 and 3 will have a consistent copy of the data.

    Note: Because this is a planned outage at Site 1, stop production I/O to Site 1 (H1) before continuing to the next step.
  2. Suspend

    This command creates the planned outage by suspending the Metro Mirror relationships between H1->H2 and the Global Mirror relationships between H1->H3. When this step is complete, the session state should be suspended and recoverable.

  3. Recover H3

    This command makes H3 Target Available. When the session state is Target Available at H3, production I/O can be moved to H3.

    Note: When Site 1 is ready to resume production, continue with the following steps. Production I/O can continue to be written to H3 through the following step.
  4. StartGC H3->H1->H2 , StartGC H3->H2->H1 , StartGM H3->H1->H2 or StartGM H3->H2->H1
    Issue this command when H1 and H2 are available and ready to be brought back into the configuration. These commands start replication back from the H3 site to the H1 and H2 sites.
    Note: The StartGM command is only available on session types allowing GM back to the H1 or H2 sites. This allows for disaster recovery capabilities while running at site 3. If the session type only supports the StartGC command at Site 3, then disaster recovery will not be available until moving production back to Site 1 or Site 2.
    Note: When you are ready to switch back to Site 1, stop production I/O on H3 before continuing to the next step. When running in Global Copy mode, it is recommended that you do the next step once all pairs are close to being synchronized, to minimize the time it will take to suspend the session consistently.
  5. Suspend

    This command suspends the relationships to Site 1 and Site 2 consistently. When this step is complete, the session state should be suspended and recoverable.

  6. Recover H1
    This command makes H1 Target Available. When the session state is Target Available at H1, production can be switched back to H1.
    Note: Optionally the session can be recovered to Site 2 as well.
  7. Start H1->H2 H1->H3

    This command will resume copy from Site 1 back to sites 2 and 3. Once the session reaches a Prepared state, there will be a consistent copy on Site 2 and Site 3.

Procedure for cascaded Metro Global Mirror session type

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Procedure

  1. Start H1->H2->H3

    Issue this command to begin Metro Global Mirror on your system when the production I/O is running on H1. Once the session is in a Prepared state, both sites 2 and 3 will have a consistent copy of the data.

    Note: Because this is a planned outage at Site 1, stop production I/O to Site 1 (H1) before continuing to the next step.
  2. Suspend

    This command creates the planned outage by suspending the Metro Mirror relationship between H1->H2. When this step is complete, the session state should be suspended and recoverable.

  3. Recover H3

    This command makes H3 Target Available. When the session state is Target Available at H3, production I/O can be moved to H3.

    Note: When Site 1 is ready to resume production, continue with the following steps. Production I/O can continue to be written to H3 through the following step.
  4. Start H3->H1->H2

    Issue this command when H1 and H2 are available and ready to be brought back into the configuration. Changes from production at the remote site (H3) flow from the local site (H1) to the intermediate site (H2). The H3-H1 and H1-H2 pairs are Global Copy. The session will remain in a preparing state.

    Note: While the session is Preparing, you can decrease the amount of time that production I/O has to be stopped by waiting for progress on the H3-H1 role pair to be at or near 100%. The next step will drive H3-H1 to sync, which depending on the percentage of the copy that is complete, can take a significant amount of time. When you are ready to switch back to Site 1, stop production I/O on H3 before continuing to the next step.
  5. Suspend

    This command suspends Global Copy relationship between H3->H1 and H1->H2. When this step is complete, the session state should be suspended and recoverable.

  6. Recover H1

    This command makes H1 Target Available. When the session state is Target Available at H1, production can be switched back to H1.

  7. Start H1->H2->H3

    This command will resume copy from Site 1 back to sites 2 and 3. Once the session reaches a Prepared state, there will be a consistent copy on Site 2 and Site 3.