Xsan Admin is a little wonky sometimes. This isn’t to say there are bugs, just that sometimes given the environmental factors it can be slow to respond. But once your SAN is up and running you can pretty much do all the admin tasks you’ll ever need using cvadmin rather than Xsan Admin. cvadmin is an interactive command line environment and will always need to be run with escalated priveleges (er, sudo).
So use the following command to see which Metadata Controllers are available and to see which is your primary per volume:
sudo cvadmin man
Now you can use sudo cvadmin and from within the interactive cvadmin command line to actually use the fail command to fail the current mdc over from one host to another.