The preferred controller ownership of a logical drive or array is the controller of an active-active
If the preferred controller is being replaced or undergoing a firmware download, ownership of the logical drives is automatically shifted to the other controller, and that controller becomes the current owner of the logical drives. This is considered a routine ownership change and is reported with an informational entry in the event log.
There can also be a forced failover from the preferred controller to the other controller because of I/O path errors. This is reported with a critical entry in the event log, and will be reported by the Enterprise Management software to e-mail and SNMP alert destinations.
The preferred owner for a logical drive is initially selected by the controller when the logical drive is created. Use the Array >> Change >> Ownership/Preferred Path pull-down menu option to change the preferred controller ownership for a selected array. To change the preferred controller ownership for a logical drive, use the Logical Drive >> Change >> Ownership/Preferred Path pull-down menu option.
To shift logical drives away from their current owners and back to their preferred owners, use the Storage Subsystem >> Redistribute Logical Drives option.