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Example—Failing back to the original Primary using fast failback

In this example, the Primary host seattle has restarted after an unexpected failure. After the failure, the Primary role was taken over by the Secondary host london. Each data volume on the Secondary london has a Data Change Map (DCM) associated with it.

This example explains how to failback when fast failback is enabled on london by selecting Auto fast failback in the Takeover wizard or when Fast failback was selected.

An application is running on london and incoming writes are logged to its DCM. This example shows how to fail back to the original Primary seattle using the fast-failback feature.

 To fail back to the original Primary using fast failback

  1. If Auto fast failback was selected in the Takeover task when taking over from the original Primary seattle, go to step 5; If Fast failback was selected, go to the next step.
  2. From the tree view, select the name of the RDS for which you want to replay the failback log. For example, hr_rvg.
  3. Choose Replication > Replay Failback Log. To use the pop-up menu, right-click the name of the RDS.
  4. Click OK. When the synchronization completes, go to the next step. You can check the status of the synchronization using the RDS view.

    The Replay Failback Log task synchronizes the data volumes in the new Secondary RVG hr_rvg on seattle with the data volumes in the new Primary RVG hr_rvg on london using the fast-failback feature. This step is not required if Auto fast failback was selected in the Takeover task when taking over from the original Primary.

  5. At a convenient time, after verifying that the synchronization has completed, stop the application on the new Primary london.
  6. Migrate the Primary role from the new Primary host london to the original Primary host seattle using the Migrate task (Replication > Migrate). For instructions, see Migrating the Primary role.

    Replication from the original Primary seattle to the original Secondary london is started by default after the migration is completed.