Apple Xsan 1.4 - Manual (Page 129)

Chapter 5 Managing Metadata Controllers 129
5 In Xsan Admin, change the role of the computer from Client back to Controller.
If you want to switch control of the volumes back to the controller with the new IP
address (they’re currently hosted by the standby controller), stop and restart them.
You can also force the switch from the command line by typing:
$ sudo cvadmin -e ”fail volume“
where volume is the name of an Xsan volume.
Upgrading Controller Software
If your configuration includes a standby controller, you can upgrade the Xsan software
without interrupting the SAN. Xsan controller software is always compatible with the
preceding version of the client software (controllers can be one version ahead of
clients). So, you can upgrade your controllers first and your client computers will
continue to work until it is convenient to upgrade them to the same version.
Important: The following instructions work only if you are upgrading from the most
recent previous version of Xsan (for example, from Xsan 1.3 to Xsan 1.4). If you’re
skipping a version by upgrading from Xsan 1.1 or 1.2 to Xsan 1.4, the failover method of
avoiding SAN interruption won’t work, and you’ll need to unmount and stop Xsan
volumes before upgrading.
For more information about migrating your SAN controllers, clients, and storage to
Xsan 1.4 from an earlier version of Xsan, including tips for upgrading with minimum
impact on existing storage, see the Xsan Migration Guide at www.apple.com/server/
documentation/.