Apple Xsan (upgrading to Xsan 1.4) - Manual (Page 13)

Chapter 2 Upgrading to Xsan 1.4 on Mac OS X version 10.4 13
Step 2: If needed, migrate controllers to the equivalent Tiger version of Xsan
If your controllers were already running Xsan on Mac OS X v10.4 before you started this
upgrade, go on to Step 3 on the next page.
If you upgraded your controllers from Mac OS X v10.3 Panther to v10.4 Tiger in Step 1
on the previous page, you need to migrate the old Panther version of Xsan to the same
version for Tiger. So, for example, if you were running Xsan 1.1 for Panther on Mac OS X
v10.3 and have upgraded the operating system to Mac OS X v10.4.7, you need to
upgrade to Xsan 1.1 for Tiger.
Important: If you want your SAN volumes to be available to clients during the upgrade,
upgrade the controllers one at a time so that there is always a standby controller to
take control of any volume currently hosted by the controller you are upgrading.
To upgrade Xsan on the controllers:
1 Upgrade the controller to its equivalent Tiger version of Xsan.
If the controller is connected to the Internet, you can open the Software Update pane
of System Preferences, click Check Now, select the Xsan update with the same version
as was installed on Panther, and click Install.
If the controller is on a private network, you can use a computer that is connected to
the Internet to download the update from www.apple.com/support/downloads/,
transfer the installer to the controller computer, and run it.
2 Restart the controller when prompted by the installer.
Any volume currently hosted by the controller fails over to a standby controller.
3 Repeat steps 1 and 2 above for each controller on your SAN.