Craig,
Turn on accounting on the server, "Set Accounting On", & read the flat file
"dsmaccnt.log" created by the server.  It generates a line at the
termination of each client session in this log.  The above information is
for the AIX ADSM server.  It gives Node name, USERID, stop time, stop date,
duration, files backed up, K bytes backed up, wait time for offline media,
communication time, ..... you get the idea.  AND it is all in 1 location.