This is a different error than before. Which tells me the log maybe corrupted on the original hd. Putting the old drive back and try repairing the log.
Doing a search on google there are multiple hits for "failed to locate log tail".
http://oss.sgi.com/archives/xfs/2002-11/msg00386.html said to try "xfs_repair -L" to repair the log. THIS FALLS UNDER SERIOUS XFS DAMAGE.
One user reported reloading the kernel corrected the problem. Which re-installing the gsu may corect the probem. You do have the CD or the GSU file Dont you. If not contacting adaptec may be your only option.
*** Since I have no experience in the Guardian OS, I would advise contacting Adaptec and pay for support if you must have the data, and you have no backup or snapshots.
But please keep up posted if you find solution. So we may learn and pass it on to others.