Xsan 2.2 is having a bit of a problem with serving up files with Extended Attributes over SMB volumes that are stored on an Xsan according to a recent knowledge base article. The fix (other than not using files with Extended Attributes on Xsan volumes that are shared up over SMB is to enable stream support in the /etc/smb.conf file.
To do so, open /etc/smb.conf and then change the stream support = yes setting to stream support = no. This isn’t to say that all of your problems will magically vanish, but it should help to provide some relief until the next update.