40gb Tapes (Compressed) Showing 18.6gb as Max

[gpcfb07]

Hi,

I'm utilizing HP dds-4 tapes with a compressed capacity of 40gb with BackupExec 9.1. A few months ago, I was approaching the 40gb max, so I reduced the size of my backups. They have slowly crept back up in size, but now, BackupExec is reporting the total capacity to be 18.6gb with a 1:1 compression ratio. As a result, my backups are failing, due to them overcoming the 18.6gb reported maximum. How do I go about utlizing the full 40gb again?

Thank you.

 

[steveot]

That sound right I just check my and report 18 GIG that the native format. If your runnig a backup check the job history does it go past 40gig or close to it. Put another tape in ad let the job finish to get a total byte count.

 

[gpcfb07]

Thank you for checking. We have a drive cascade setup (backup job distributed between two tape drives) and both of these drives are utilizing a dds-4 tape (20gb uncompressed/40gb compressed). We used to get 70+gb backups with the two drives. Now, it requests "overwritable media" when it hits about 52gb. Most of the data being backed up is highly compressible (Word documents, etc.). Is there any way to improve the compression ratio?

 

[gpcfb07]

Anyone have any idea why we're not getting a better compression ratio, if it's adjustable, etc. As I stated earlier, a few months ago, we used to get approx. 70gb backups on two 20g/40gb(compressed) tapes. Now, we're only getting approx. 52gb. The same types of files are still being backed up, so I would estimate that it's not an issue with file compression capability.

Thanks.

 

[Spirit]

If its a 40GB compressed then it would be 20GB uncompressed so there "probably" isn't a problem as such.

I would hazzard a guess that thye files you're backing up aren't compressable; can I ask which types you are backing up?

Also are you using Hardware or Software compression or both?

If you think the files should compress further then try the usual suspects, uopdate the firmware, make sure you've got the latest SW updates.

Iain