Failing back using identity

If your source experiences a failure, such as a power, network, or disk failure, your target machine will stand in for the source while you resolve the source machine issues. During the source machine downtime, data is updated on the target machine. When your source machine is ready to come back online, the data is no longer current and must be updated with the new data from the target machine.

Before you begin to restore to the original source, resolve the issue(s) that caused the failure.

If the source server has to be rebuilt, follow the instructions in Rebuilding the source.

1. After repairing/rebuilding the source server offline, bring the server up but leave the network connection disabled by unplugging the cable or disabling the network interface adapter.
2. Stop all of the services on the source so that you can overwrite the data with the newer data on the target. Because the source server cannot communicate with a domain controller because its network connection is still inactive, this will take longer than normal. The following lists the services that must be stopped, in the order in which they must be stopped. Stop the services appropriate to your application.

3. On the target, open the Failover Control Center (Start, Programs, Double-Take, Availability, Double-Take Availability Failover Control Center).
4. Double-click the target machine that is currently standing in for the failed source to login.
5. Highlight the failed source and click Failback. The failback script created earlier will run automatically. During failback, Windows Event Viewer and the Double-Take Availability log record the failback events. When failback is complete, the services will be stopped on the target and the Failback Complete dialog box will appear.
6. Do not select Continue or Stop at this time. First, reconnect the source to the network.
7. After the source is available on the network, select Continue (to restart monitoring) or Stop to disable monitoring.
8. To begin the restoration process, open the Double-Take Replication Console on the target (Start, Programs, Double-Take, Double-Take Replication Console).
9. Login to the source machine by double-clicking on it.
10. Right-click on the original connection and select Disconnect.

11. Select Tools, Restoration Manager.
12. Complete the appropriate fields on the Restoration Manager.

• Original Source—The source where the data originally resided.
• Restore From—The target that contains the replicated data that users have been updating.
• Replication Set—The name of the replication set.
• Restore To—The source where the data will be restored to.

13. Disable Only if backup copy is more recent. This option must be disabled because if the services were stopped on the source after the time they were stopped on the target, the source files will have a more recent date and time and the target files will not be restored.
14. Identify the correct drive mappings for the data and any other restoration options necessary.
15. On the Orphans tab, select to move or delete orphan files on the source. Orphan files, such as out-dated transaction logs, may keep the database from starting on the source.
16. Verify that the selections you have made are correct and click Restore. The restoration procedure time will vary depending on the amount of data that you have to restore.

When the restoration process is complete, the restoration status information will no longer appear in the right pane.

17. If you are performing a failback for an Exchange server, continue with Rehoming the Exchange objects to the source to complete the restoration process.
18. Continue to Re-enabling protection to complete the restoration process.

After the restoration is complete, you will need to run the Exchange Failover utility (exchfailover.exe) to rehome the informational store databases to the source. For more information about using the Exchange Failover utility, see Using the Exchange Failover (EFO) Utility.

1. From a command prompt on the source, run the post_restore_<source server name>_<target server name>.bat file that Application Manager automatically generated.
2. Restart any Outlook clients so that they can access the source.

To re-establish protection of the Exchange data on the source, create a replication set, re-establish the Double-Take connection to the target, and begin failure monitoring as documented earlier in the procedure.

If DNS failover was selected, the clients will have to wait for the IP cache to expire, or type in “ipconfig /flushdns” in a command window. This time can be adjusted by lowering the TTL (Time to Live) setting within your DNS server’s configuration. For more information, refer to your DNS server documentation.