< Previous  | TOC | Index | Next  >

Failback options

The Takeover task provides the following options to fail back to the original Primary. Select the required option depending on the method you plan to use for failback.

• Fast Failback—This is the default and is the recommended option. This option enables fast failback. Use this option if you want to incrementally synchronize the original Primary with the new Primary. However, conversion of the original Primary to a Secondary and synchronization of the original Primary data volumes with the data volumes on the new Primary is not done automatically.

  To synchronize the data volumes on the original Primary and convert the original Primary to a Secondary, use the Replay Failback Log task (Replication > Replay Failback Log) on the RDS.

• Auto fast failback—Use this option if you want to convert the original Primary to a Secondary after the original Primary becomes available and also to automatically synchronize the data volumes on original Primary, which is now the new Secondary, using fast failback.
• No fast failback —If you choose this option, you must synchronize the original Primary after it becomes available. Use this option if you are sure that the original Primary will not recover or if most of the data on the new Primary is going to change while the original Primary is unavailable.

  ---

    Tip   We recommend that you use the Fast failback option to synchronize the original Primary with the new Primary. For instructions, see Failing back using fast-failback synchronization.

  ---

 To take over from the original Primary to the Secondary

1. Make sure you have logged on to the Secondary host. To log on to a host from VVR VEA, choose File > Connect and specify the name of the host to which you want to connect.
2. From the tree view, select the name of Secondary host whose role you want to change to Primary. For example, london.
3. Choose Replication > Takeover. To use the pop-up menu, right-click the name of the RDS and select Takeover.

Click the thumbnail above to view full-sized image.

4. Complete the Takeover dialog box as follows:

    

   Options:  Fast Failback  Auto fast failback  No fast failback

   By default, Fast failback is selected. If this option is not appropriate, select the required option.  To enable fast failback logging only, select Fast failback. You can synchronize the data volumes on the original Primary and convert the original Primary to a Secondary using the Replay Failback Log task (Replication > Replay Failback Log). To convert the original Primary to a Secondary after it becomes available, and also automatically use the DCM to synchronize the data volumes on the original Primary using fast failback, select Auto fast failback. To change the role from Secondary to Primary without enabling fast failback, select No fast failback. Select this option if you are sure that the original Primary will not recover or if most of the data on the new Primary is going to change while the original Primary is unavailable.

5. Click OK. A message that indicates whether the takeover succeeded or failed is displayed.
6. Start the application on the new Primary. Starting the applications on the new Primary after a takeover may require an application recovery to be run.

Notes:
If you want to use the fast-failback feature, make sure that the data volumes on the Secondary host have associated DCMs. If fast failback is enabled, the RDS View displays the value DCM in the Logging To column for the original Primary.