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Failing back using automatic synchronization

 To fail back to the original Primary using automatic synchronization

1. Convert the original Primary to a Secondary using the Make Secondary task (Replication > Make Secondary).

   For detailed instructions, see Converting a Primary to a Secondary.

2. Synchronize the data volumes on the original Primary with the data volumes on the new Primary using the Synchronize RVG task (Replication > Synchronize RVG).

   For detailed instructions, see Synchronize the Secondary RVG with the Primary RVG.

3. Stop the application on the new Primary.
4. Migrate the Primary role from the new Primary host to the original Primary host. Replication from the original Primary to the original Secondary is started by default. See Migrating the Primary role.

Converting a Primary to a Secondary

Use the Make Secondary task to convert an original Primary to a Secondary. The Make Secondary task can be launched from the original Primary only when one of its Secondary hosts has taken over the Primary role.

The Make Secondary task is used in the failback procedure to fail back to the original Primary. When the original Primary restarts, use the Make Secondary task to convert the original Primary to a new Secondary. Stop the application if the application restarts automatically when the Primary restarts.

  Note   Use the Make Secondary task to fail back to the original Primary only if Fast failback was not selected during the takeover from the original Primary.

 To convert an original Primary to a Secondary

1. From the tree view, select the name of the original Primary host that has restarted and whose role you want to convert to Secondary. For example, seattle.
2. Choose Replication > Make Secondary. To use the pop-up menu, right-click the name of the RDS.
3. Complete the Make Secondary dialog box as follows:

    

   New Primary

   From the drop-down list, select the name of the new Primary. For example, london.  If the original Primary no longer has a list of its original Secondary hosts, then enter the name in the box that is provided.  The value in the entry field takes precedence over the selected value in the selection box.

4. Click OK. A message that indicates whether the Make Secondary task succeeded or failed is displayed.

    

   Notes:
   Before using the Make Secondary task, make sure that you stop all the applications that use the data volumes on the original Primary. Also, ensure that none of the data volumes are open.

Synchronize the Secondary RVG with the Primary RVG

Use the Synchronize RVG task to synchronize the data volumes on the Secondary with the data volumes on the Primary. The Synchronize RVG task can be used in the failback procedure to synchronize the data volumes on the original Primary with the data volumes on the new Primary using automatic synchronization.

 To synchronize the Secondary RVG with the Primary RVG

1. Select the Secondary host name from the tree view.
2. Choose Replication > Synchronize RVG.
3. Click OK. The status of the synchronization is displayed in a message box.

Note:
While resynchronization is in progress, the RDS View displays the values resync in progress and DCM (autosync) in the Replication Status and Logging To columns respectively.