Compression on Ultrium Tape Drives

[Marko Busic_1]

Hi!

We have HPUX 11i machine(s) and STK700 tape library with Viper200 Ultrium drives.

The HPUX automatically created appropriate /dev/rmt/cXtXdXBESTxx device special files, but the compression on that device files does not work.

The output from lssf is:

# lssf c10t0d0BESTnb
stape card instance 10 SCSI target 0 SCSI LUN 0 berkeley no rewind best density available at address 0/10/0/0.1.31.255.0.0.0 c10t0d0BESTnb

In Viper manual, there is a suggestion to do a mkfs with â c 1 option, which enables compression. We have created the special files that way, and lssf gives:

# lssf /dev/rmt/11cnb
stape card instance 10 SCSI target 0 SCSI LUN 1 berkeley no rewind compression type 1 best density available at address 0/10/0/0.1.31.255.0.0.1 /dev/rmt/11cnb

Compression works on those device special files.

The question is: why the compression does not work with the default created device special files, even they have â BESTâ in their names, which indicate that the compression should have been switched on? How to change the behavior of insf, so that compression is enabled by default?

Thanks in advance.

Best regards,
Marko B

[Pete Randall]

Hi Marko,

There was a similar discussion recently:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=297810


Pete