Backup Issue

[Natasha Wirth]

hi i've got a HP StorageWorks Ultrium 920 tape drive and I'm trying to determine where my backup issue lies. I cannot seem to backup more than 420GB even though I'm using 400/ 800GB tapes...should compression on the tape drive be set in a specific way?

[Lewis Finch · Accepted solution]

the drive uses hardware compression be default. Make sure you d not have software compression set. could it be the data you are backing up is already compressed? You cannot compress it more if that is the case.

[Natasha Wirth]

Thanks for that. We're backing up dwg, framemaker and jpg files. Is the hardware compression not 'clever' enough to differentiate betw the compressed files and uncompressed ones? Therese currently no software compression, nor any NTFS compression

[Lewis Finch]

Here is an excellent document that explains compression. Hardware compression is favored over software compression.

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=lpg50460

[Natasha Wirth]

Hi there, I've tried a number of different configs (no compression, hardware only compression and software only comrpession). None of them let me backup more than 432GB still onto the tape. Is there something else I can try? Actually looking at tape capacity its giving me 391GB max which I know is untrue as I'm backing up successfully to 431GB, just when it reaches 432GB is when it crashes

[Lewis Finch]

download Libray and Tape Tools diagnostic from this site.Make sure you have removable storage service stopped as well as your backup software service. Install this tool and you can test your drive to see what compression you are getting.

http://h20000.www2.hp.com/bizsupport/TechSupport/DriverDownload.jsp?pnameOID=406731&locale=en_US&taskId=135&prodSeriesId=406729&prodTypeId=12169