just to add : NBU runs this command every 12 hrs.
From : http://www.symantec.com/docs/TECH135182
"The purpose of the bpexpdate -deassignempty command is to return a tape to scratch if all of the images on the tape have expired before the tape's expiration time has been reached"
"If the bpexpdate -deassignempty command is not being run, empty tapes (which no longer hold valid images) will not be made available for new backups until the tape's expiration time - this may be a long time in the future (or possibly never, if the tape's expiration time is infinity)"
-deassignempty should not be run on a tape that contain valid images. You can always run "bpimage -cleanup -allclients" if you can't wait for Netbackup to do the periodic release of media.
Hope that answer the qustion
Best Regards
Nicolai
