Failover without losing the Tiebreaker configuration

Failover is supported if either the Primary or Mirror instance goes down, but the Tiebreaker instance remains operational.

The IBM Storage Scale Mirror configuration, with Primary, Mirror, and Tiebreaker instances, is resilient to a complete failure of any single hardware site. If all of the storage volumes in either the Primary or Mirror instance become unavailable, IBM Storage Scale performs a transparent failover to the remaining set of storage volumes and continues serving the data to the surviving subset of nodes with no administrative intervention.

When only the IBM Storage Scale Primary instance becomes unavailable, you can run the Move Primary To Rack operation on the IBM Storage Scale Mirror instance. This operation moves the IBM Storage Scale primary server designation to the IBM Storage Scale Mirror instance.

Make sure that you also move the cluster manager and file systems manager to the Mirror instance. For more information about the operations to use to make these cluster changes, see Failover active-active operations.

If you have a IBM Storage Scale server instance that was deployed with IBM Storage Scale Pattern 1.2.15.0 or older, run this command from the command line for any of the IBM Storage Scale server nodes to update the cluster and file system manager:

su - gpfsprod -c 'sudo /usr/lpp/mmfs/bin/mmchmgr -c nodeIP' to make the nodeIP the cluster manager.

su - gpfsprod -c 'sudo /usr/lpp/mmfs/bin/mmchmgr fileSystemName nodeIP' to make the nodeIP manager for fileSystemName.

When only the IBM Storage Scale Mirror instance becomes unavailable, you can run the Move Secondary To Rack operation on the IBM Storage Scale Primary instance. This operation moves the IBM Storage Scale secondary server designation to the IBM Storage Scale Mirror instance. For an AIX® cluster, there is only one node, so the primary is moved to the Tiebreaker instance.

Make sure that you also move the cluster manager and file systems manager to the Primary instance. For more information about the operations to use to make these cluster changes, see Failover active-active operations.

If you have a IBM Storage Scale server instance that was deployed with IBM Storage Scale Pattern 1.2.15.0 or older, run this command from the command line for any of the IBM Storage Scale server nodes to update the cluster and file system manager:

su - gpfsprod -c 'sudo /usr/lpp/mmfs/bin/mmchmgr -c nodeIP' to make the nodeIP the cluster manager.

su - gpfsprod -c 'sudo /usr/lpp/mmfs/bin/mmchmgr fileSystemName nodeIP' to make the nodeIP manager for fileSystemName.