HP SureStore DAT40 with TapeWare

[Dennis Chong]

Hi, currently i am using hardware compression on my DAT40 TapeDrive running on TapeWare with Software Compression OFF under Win2000 Server...
Problem is my selected backup Objects is 28Gb but i am onli able to backup to less than 26Gb
which is even less than 75% of 40GB....
Does anyone have an answer?
Attached is the Backup Job Log file

[Eugeny Brychkov]

Dennis,
native DAT40 capacity is 20GB - this means that turning off compression(s) you'll be able to backup 20GB of your data. You can store 40GB with compression ratio 2:1. But are you sure that your data you're currently backing up is compressible with 2:1 ratio? 26/20=1.3 (not 2). Try HP LTT compression and media tests http://www.hp.com/cposupport/information_storage/support_doc/lpg50128.html
Eugeny