Failing back
Similar to failing over, failing back depends on the state the system was in when failing over.
If there was no configuration change, no disks or nodes lost, and only a IBM Storage Scale Primary or Mirror instance is down, you can run the Recover Lost Connection operation. This operation restarts the disks for the instance, restarts the nodes of the instance, and reassigns the IBM Storage Scale primary or secondary server role to the instance depending on whether it is a Primary or a Mirror instance. The operation also performs any disk startup as needed. This operation must be run on the Primary or Mirror instance that is down.
However, if either the Primary instance, or the Mirror and Tiebreaker instances are down, but there is no fatal damage to either nodes or disks, run the Become Replicated Cluster operation on the Primary or Mirror instance that is down.