> I have a Seagate Scorpion 8 DAT tape drive. I need to turn on
> hardware compression, but I can't figure out how. Can someone help me
> out? I've tried "mt -f /dev/st0 compression on" and "mt -f /dev/st0
> setdensity 0x24" but nothing seems to help. It is a DDS-2 drive (8GB)
> that is stuck on DDS-1 (2-GB) mode.
I don't know that particular Seagate model, but check its manual
for jumpers or DIP-switches controlling compression.
The way I see it is, if you disabled HW compression by jumper,
you cannot control it by the mt tool - but if enabled, then mt
should have control to turn it off on demand.
At least that's the way my Archive Python DDS-1 and the Sony DDS-3
drive work, as well as some HPs in the office.
BTW : with my version of mt, it's "... datcompression 0" to disable,
1 just to print the compression status, and any other number to
enable.
About the media : Normally, you don't need to set densities for
the different DDS media manually - this should be auto-sensed
by the "Media Recognition System" of the tape cartridges.
With an older distro - and hence old mt version - "mt setdensity"
also doesn't seem to work, but the Sony obviously adjusts that
automatically. I verified already that you can write 4 GB (native)
to DDS-2 and some 12 GB to DDS-3 media. Thus, it's only a "cosmetic"
display issue, at least fo me.
HTH
Juergen