BE 11d not compressing DLT tapes

[JBruyet]

Hey all,

I'm having a problem with my BE 11d. It's running on a ProLiant server, backing up to a Maxell DLT IV tape in an HP VS80 DLT drive. I can successfully backup this server as long as the total amount of data being backed up stays below 38 gigs or so (the drive and the tapes are 40/80). Once I go over 38 gigs the tape pops out and BE asks for another tape.

I've tested the drive and it tests out at a compression ratio of 2.27:1. I've checked my backup job and the Compression Type is "Hardware (if available, otherwise software)." Is there somewhere else I need to check to enable compression on my backup job?


Thanks,

Joe B

 

[mofusjtf]

What compression are you using? Software or hardware? I typically set BE to Hardware Compression (otherwise, none).

But I also do not base my backup on compression. If I need to backup 100 GB's I make sure I can get 100 GB's native on my backup device. Any compression is viewed as a bonus.

 

[JBruyet]

mofusjtf,

The compression I'm using is:

Hardware (if available, otherwise software)

I'll change it to:

Hardware (if available, otherwise none)

I originally had plenty of storage space on a 40 gig tape (40 uncompressed, 80 compressed), but 40 gigs just isn't going to cut it any longer. More and more files are being stored on this server so I need to try to get compression working. I've budgeted for a larger tape drive for next year, but that won't help me now.

Thanks for the help,

Joe B

 

[mofusjtf]

You will find that you are going to spend more time battleing compression than it is worth. Compression all depends on the the type of data you are trying to compress. Databases will compress well while other files may not. Remember that 40/80 data capacity is tested in a perfect lab environment. You will rarely get that type of compression (Despite what your backup software may say). Base your strategy off native capacity and treat any compression as a bonus.

I wouldn't budget for a tape drive. It is old technology. Look at disk based backup solutions. If you use Dell servers you can look at the RD1000. Great solution. CRU-Data port has similar solutions and Cybernetics has high-end stuff.