Sometimes you just need a small SAN for testing... Times when you don’t have fiber channel and you don’t need to provide access to multiple clients, like maybe if you're writing an article for Xsanity on an airplane. Now this volume is not going to be supported (or supportable) by anyone and nor should it be (so don’t use it for real data), but you can use USB and FireWire drives for a small test Xsan…

To get started we’re first going to destroy the contents of the drive, so be sure it’s backed up. Go ahead and connect the empty USB or FireWire media to be used and open up Disk Utility. Here, locate the disk in question and click on it (make sure not to click on the volume). Click on the Partition tab in Disk Utility and set the format to Free Space to prepare the drive for labeling.

If you’re using Xsan 1.4.x then you should now see the LUN in Xsan Admin and be off to the races. But, if you’re using Xsan 2.x then you’re going to need to go ahead and label the LUN from the command line. To do so, open Terminal.app from /Applications/Utilities. Now go ahead and type in the following command, which should show you all your available LUNs:

cvlabel -l

Next, type the following, which will dump your label information out to a standard text file called labels

cvlabel -c >labels

Now that you have your file open it in your favorite text editor and change the very first text field to read the name that you want your LUN to be labeled as, within Xsan Admin. Once you’re satisfied save the file. Now, use the following command, which will read the file you just edited and then label the LUN for use with acfs using the name you just provided, making it appear in Xsan admin:

cvlabel labels

Now you can open up Xsan Admin and build a new volume using the label. This is a great way to do testing of the Xsan commands, but the volume will be terribly slow, will corrupt easily and is not appropriate for absolutely positively anything other than testing.