We use ORBiT Software's BACKUP/3000 product.  We've used it for a couple
of years.  Their product offers options for:
 
1.  Online Backup:  While users are logged on, you can stream the online
backup  job.  It logs file changes of files that it has backed up.  When
it finishes, it prompts the console for when it can synchronize, at which
point it stores the log files and directory info.
 
2.  Multiple tapes:  No need to decide which files go on which tape.
BACKUP/3000 takes care of that for you.
 
3.  Zero Down Time:  This is similar to online backup, but it doesn't
require users to log off at synchronization.  It just pauses their work
for a moment while it stores log data.
 
Otherwise, BACKUP/3000, with normal stores, has efficiencies which
expedite the store.  Good Luck!