I have a situation where we are using a small DLT library to perform backups
with NetBackup.  The library holds 10 DLT tapes and we rotate the tapes out
once a week.  Our NT admin that manages backups changed the tapes last
Friday, but forgot to change the logical location of tapes within the Media
manager.  We are not using barcodes, and each tape was labeled manually in
the beginning to specify a certain tape number on the label to match the
hand written label.

We had backups continue for some classes where the tape was relabeled to
match the logical tape location.  ie Tape 001 was relabeled 017.  Some of
the other classes failed because it couldn't assign the correct tape.

1.  When and why does NetBackup physically relabel tapes, and is there a way
to prevent it from writing over an existing label?
2.  To alleviate the problem, we corrected the logical location of tapes
within media manager, and I am currently using bplabel from the command line
to verify the tape label.  Is there a way to relabel tapes from the GUI?
(NT admins don't typically like the command line like us Unix guys do.  ;-)
)  Is there another way other than bplabel to verify what the label on a
tape is?  
3.  Is there a suggested best practice to alleviate this problem from
happening in the future?

Thanks,
Dan