Video Screencast Help

HP DAT 72 drive gets no compression on backup

Created: 02 Feb 2005 • Updated: 22 May 2010 | 2 comments

I've just upgraded to version 10 and have the same problem existing from version 9 and 9.1. I have a HP DAT drive and the tapes are only coming up as having 33 GB available and a compression ratio of around 0.926:1. Becuase of this I can't get any more data than 34 Gig onto a single tape. I have the latest HP drivers installed for the device, has anyone got any ideas why this is?


Comments 2 CommentsJump to latest comment

Abhinav Bindroo's picture

What is the native/compressed capacity of the tapes ?

Follwoing technote might be useful

Additional Information
Higher and lower compression will occur depending on the type of files being backed up and the compression method used for the same.Each data type has its own compression ratio, and, therefore, there is no standard achievable for the total compression ratio that results.
Hardware compression will work only when the tape device supports it.

Try installing the latest Veritas drivers for the device

Sagar Kamat 2's picture

The best way to verify compression is, to use NTbackup instead of Backup Exec with the same parameters to do a backup job.

Note: To use the device with NTBackup, please uninstall the VERITAS device drivers and install the latest OEM drivers.

If the same compression is achieved, then the hardware is not achieving the desired compression or it may the best the hardware can compress.