On Wed, Aug 07, 2002 at 02:46:21PM -0700, Paul G. Allen wrote:
> My changer has an HP35480A DAT drive. Should I enable drive compression
> for use with Amanda and NOT use software compression for backups, or
> should I disable the drive compression and use software compression for
> backups? The compression on these drives is enabled/disabled with DIP
> switches. It can be controlled through software, IF the SCSI driver
> supports it and it looks like scsi-changer does not (I have no
> indication that I am able to turn the drive compression on/off, even
> though the DIP switches are currently set to allow it).

Actually, the DIP switch options are what state it "powers up to" and
"whether" it can be changed by software.

Think of the changer and the drive as two seperate "devices".
The changer doesn't deal with compression, so scsi-changer doesn't either.

How you change compression settings is OS and driver dependant.  Common
ways are through device names (eg. solaris had drive 0l and 0c type names
showing "l"ow density and "c"ompressed density) and by mt(1) command line
arguments (eg. I think linux uses this).

-- 
Jon H. LaBadie                  jon AT jgcomp DOT com
 JG Computing
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