Apple Xsan 1.1 - Manual (Page 20)

20 Chapter 3 Upgrading to Xsan 1.1 on Mac OS X v10.4 “Tiger”
Step 3: Upgrade all controllers to Xsan 1.1 on Mac OS X v10.3.9
Now that the controllers are running Mac OS X v10.3.9, you can upgrade the Xsan
software to Xsan 1.1.
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 one controller to Xsan 1.1.
If you have an Xsan 1.1 installation disc, insert it in the computer and double-click
Install Xsan.mpkg.
If you don’t have the disc but the computer is connected to the Internet, you can open
the Software Update pane of System Preferences, click Check Now, select the Xsan
Update version 1.1 update, 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 on each controller in your SAN.