System-Level Fault Tolerance (Clustering/Network Load Balancing) - Restoring an Entire Cluster to a Previous State

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Changes to a cluster should be made with caution and, if at all possible, should be made in a lab environment first. When cluster changes have been implemented and deliver undesirable effects, the way to roll back the cluster configuration to a previous state is to restore the cluster quorum to all nodes. This process is simpler than it sounds and is performed from only one node. There are only two disadvantages to this process:

• All the cluster nodes that were members of the cluster previously need to be currently available and operational in the cluster. For example, if Cluster1 was made up of Server1 and Server2, both of these nodes need to be active in the cluster before the previous cluster configuration can be rolled back.

• To restore a previous cluster configuration to all cluster nodes, the entire cluster needs to be taken offline long enough to restore the backup, reboot the node from which the backup was run, and manually start Cluster Service on all remaining nodes.

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Note - If a cluster node is in a failed state, the cluster configuration cannot be rolled back. Refer to the "Restoring a Single Node After a Complete Server Failure" or the "Restoring the Failed Node Using the ASR Restore" sections to restore a failed cluster node to operational status and then restore a previous cluster configuration as shown here.

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To restore an entire cluster to a previous state, perform the following steps:

1. Log on to the cluster node using an account that has the right to back up the system. (Any Local Administrator, Domain Administrator, or Cluster Service account has the necessary permissions to complete the operation.)

2. Click Start, All Programs, Accessories, System Tools, Backup.

3. If this is the first time you've run Backup, it will open in Wizard mode. Choose to run it in Advanced mode by clicking the Advanced Mode hyperlink. After you change to Advanced mode, the window should look like the one in Figure 31.13.

4. Click the Restore Wizard (Advanced) button to start the Restore Wizard.

5. Click Next on the Restore Wizard Welcome screen to continue.

6. On the What To Restore page, select the appropriate cataloged backup media, expand the catalog selection, and check System State (refer to Figure 31.18). Click Next to continue.

7. If the correct tape or file backup media does not appear in this window, cancel the restore process. Then, from the Restore Wizard page, locate and catalog the appropriate media and return to the restore process from step 4.

8. On the Completing the Restore Wizard page, select the Advanced button to configure advanced restore settings.

9. On the Where To Restore page, choose to restore files to the original location and click Next.

10. A warning message will pop up stating that the restoring system state will overwrite the current system state. Click OK to continue.

11. On the How To Restore page, choose the Leave Existing Files (Recommended) radio button and click Next to continue.

12. On the Advanced Restore Options page, check the Restore the Cluster Registry to the Quorum Disk and All Other Nodes box, similar to the options selected in Figure 31.19, and click Next to continue.

13. A warning message pops up stating that this restore will replace the master version of the cluster quorum and will stop Cluster Service on all the other nodes in the cluster. Click Yes to continue.

14. On the Completing The Restore Wizard page, click Finish to start the restore.

    
    
    Figure 31.19  Selecting options for restoral.

15. When the process is complete, review the log for detailed information and click Close when finished.

16. Reboot the restored cluster node as prompted.

17. After the restored node completes rebooting and the previous cluster configuration is restored, start Cluster Service on all the remaining cluster nodes.

18. Move cluster groups as desired and close Cluster Administrator.

This chapter is from Microsoft Windows Server 2003 Unleashed, by Rand Morimoto, et al. (Sams Publishing, 2004, ISBN: 0672326671). Check it out at your favorite bookstore today. Buy this book now.

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