Sometimes you just need to restart the Xsan services on a system. For example, you rm the contents of /Library/Preferences/Xsan and don’t feel like restarting a computer and waiting for all that ProTools boot junk to fire up. So, you can just restart the services:
launchctl unload /System/Library/LaunchDaemons/com.apple.xsan.plist
launchctl load /System/Library/LaunchDaemons/com.apple.xsan.plist
Also, I now always disable Xsan in System Preferences prior to doing the restart of services. Otherwise, I find cruft happens…