Sorry I didn't mention: I am using a quantum DLTVS160 tape on a fedora core 2 
server

After doing this:

Alexander Jolk wrote:

You don't specify what OS you are working on. On Linux, try `mt -f /dev/nst0 datcompression 0' to turn it off. On Irix, you need to access the correct /dev/rmt/ device, for example.

which on my fedora core 2 turns out to be mt -f /dev/nst0 compression 0

I did this:

Paul Bijnens wrote:

Amtapetype has a test for that, with the -c option:

   amtapetype -c -f /dev/yourtape

and got this:

Writing 256 Mbyte   compresseable data:  35 sec
Writing 256 Mbyte uncompresseable data:  35 sec
Estimated time to write 2 * 1024 Mbyte: 280 sec = 0 h 4 min

which I take to mean that HW compression is off

Am I right ?

Shai
--
Shai Ayal, Ph.D.
Head of Research
BioControl Medical BCM
3 Geron St.
Yehud 56100
ISRAEL
Tel:  + 972 3 6322 126
Fax:  + 972 3 6322 125
email: shaia AT biocontrol.co DOT il