Only able to back up 19GB on on 40 GB tape

[sindoolan]

Hi
I am using Backup Exec 9.1 and 40 GB hp dds tapes. My backups have been running fine and its been backing up 30 GB of data. However since 1 backup failed it only backs up 19GB of data. Anything exceeding this and the backup fails. I have tried formatting the tape and did a test run but it says it has 19 GB online overwrite capacity.
Any ideas?
Regards
Sean

 

[mattjurado]

How much data can the drive/tapes support natively and with compression? You state its only backing up 19gb, but how much data do you have selected in your job.

I'm just making an educated guess here, but I'm going to say your drive/tapes do 20gb or 40 compressed. Usually you don't get anywhere near the rated compression with Windows, and fitting 30gb is pretty good on 40gb compressed, if my guess is accurate. If I'm on track, simply reduce the size of your backup job by a few gigs, see if it is successful, if so, time to get a bigger drive. I've seen this before, the software "reads ahead" and realizes the job is too big for one tape, so it fails.

You can also simply try a new tape if I'm off track.

Matt J.

Please always take the time to backup any and all data before performing any actions suggested for ANY problem, regardless of how minor a change it might seem. Also test the backup to make sure it is intact.

 

[BenChristian]

It sounds like compression is not working at all. Like mattjurado I'm guessing your tapes are 20GB native but you're only managing to backup 19GB. You should be able to acheive around 30GB (~1.3:1) unless you are backing up mostly images or files that don't compress well. Check to make sure you are using Hardware compression.