Changing controller ownership of a logical drive changes the preferred controller ownership of the logical drive. The preferred controller owner of a logical drive is listed under the Logical Drive >> Change >> Ownership/Preferred Path pull-down menu option with the designation of "preferred" and normally a dot next to the menu item. In certain situations, the logical drives can be temporarily moved to the other controller. Under these circumstances, the menu option uses the association dot to identify the controller that currently owns the logical drives (the current owner) and the "preferred" designation to show the preferred owner.
You can change the controller ownership of a standard logical drive or a FlashCopy repository logical drive. You cannot directly change the controller ownership of a FlashCopy logical drive, because it inherits the controller owner of its associated base logical drive.
The controller owner of the Primary Logical Drive in a Remote Mirror determines the controller owner of the associated SecondaryLogical Drive. For example, if Controller A owns the Primary Logical Drive in the primary storage subsystem, then Controller A owns the associated Secondary Logical Drive in the secondary storage subsystem. Controller ownership changes of the Primary Logical Drive cause a corresponding controller ownership change of the Secondary Logical Drive. You cannot change the controller ownership of a Secondary Logical Drive using this option.
If you select an array in the Logical View and there are association dots next to both controllers in the Physical View, select each logical drive individually to determine the "preferred" controller owner of each logical drive.
Under certain operating system environments, it might be necessary to reconfigure the multi-path host driver before an I/O path can be used. (Some multi-path drivers require an edit to recognize the I/O path. Consult your driver's documentation for more information.)
Caution: If you do not use a multi-path driver, shut down any host applications that are currently using the array to prevent application errors when the I/O path changes.
Procedure for Logical Drives
To change controller ownership of a logical drive, select a logical drive in the Logical View. Then, select either the Logical Drive >> Change >> Ownership/Preferred Path pull-down menu option, or Change >> Ownership/Preferred Path from the right-mouse pop-up menu and select the controller from the sub-menu.
Result: The ownership of the logical drive is changed. I/O to the logical drive is now directed through this I/O path.
Note: The logical drive might not use the new I/O path until the multi-path driver reconfigures to recognize the new path. Typically, this takes less than five minutes.
Procedure for Arrays
To change controller ownership of an array, select an array in the Logical View. Then, select either the Array >> Change >> Ownership/Preferred Path pull-down menu option, or Change >> Ownership/Preferred Path from the right-mouse pop-up menu and select the controller from the sub-menu.
Important: Changing ownership at the array level causes every logical drive in that array to transfer to the other controller and use the new I/O path. If you do not want to set every logical drive to the new path, change ownership at the logical drive level instead.
Result: The ownership of the array is changed. I/O to the array is now directed through this I/O path.
Note: The array might not use the new I/O path until the multi-path driver reconfigures to recognize the new path. Typically, this takes less than five minutes.