Compression

[Lance_Daschle_2]

I have looked at many of these threads but have not found a clear cut answer. I have 200 / 500 gb tapes but am only getting around 200 gb's out of them. I have turned hardware compression on and in the job properties I have it on also. When I look in the devices tab and click on the actual tape is shows only a 0.064:1 compression ratio. I would like to get as much out of this tape as I can. Thanks for any help.

[Shyam_Sundar]

Hello,

Please try using Software Compression and let us know about the results.

The following documents may be of help to you for such issues.



http://support.veritas.com/docs/199542

Also install the latest Veritas drivers from the following link :



http://support.veritas.com/docs/275676

[Jeff_Latimer]

A common problem that I have found in my experience is that network throughput is a factor. If you are backing up remote targets and the data cannot be supplied to the media server fast enough, the compression ratio suffers due to the stops and starts of the tape. I had a situation where on a 100Mbit network I was getting 227GB on a 460GB tape. I am now getting 300GB on a 1000Gbit network.

Check for network issues like duplex and speed mismatches. Where possible lock down your connection rates on both the server and port to the maximum supported. A duplex mismatch will only show up on a busy network - a backup session will create a busy network.

Just my experience... Can guarantee it will be yours...

[priya_khire]

Hello,

What tapes are you using for the backup? Since when do you get this low compression? From the devices tab, go to the properties of the drive, configuration and check if you have checked the option 'enable compression' for this drive. If not, check it.
Additionally you may try installing the latest drivers for the device and check the results. It has known to improve the compression in many cases. You can download the drivers at the following link:

VERITAS Backup Exec (tm) 10.0 - Device Driver Installer (20050315) - Includes Tape Driver Release (20050115) and Robotic Library Release (45) (Intel Only)
http://support.veritas.com/docs/275676

Hope this helps. If not, do write back to the forum. In case we do note reciev your update within two business days, this post would be marked ‘assumed answered’ and would be moved to ‘answered questions’ pool.

Regards.