Fail Over a Controller

Failover requires one controller to be in Active mode and the other controller to be in Standby mode.

A failover switches management of the array from the active controller to the standby controller.

While you can manually perform a failover, a failover can also be system driven. For example, in an iSCSI array, a failover can occur when the standby controller has better connectivity. In a Fibre Channel array, a failover will occur when the active controller loses all connectivity.
NOTE: A failover will not start automatically until connectivity to the array is lost for ~6 seconds.

You must perform a failover during a controller upgrade or when directed by support.

  1. Determine the name of the array.
    array --list
    The name of the array appears in the list.
  2. Perform the failover.
    failover --array array_name
    During the failover operation, the standby controller first goes into Solo mode, and then into Active mode. The active controller goes into Unknown mode, then into Stale mode, and finally into Standby mode. 
$ failover --array datamaster-a