Using TSM 5.1 on Solaris 8 with a Sun L20 Tape Library (using DLT8000 
drives) how can I check if TSM uses the hardware compression of the drives?

We use the TSM driver to access the drives (so there's no special driver 
for using the drives in compression mode). The only way to configure hw 
compression in TSM I found is to configure the approbate drive format in 
the device class (DLT35C or DLT40C) (Is there another way to configure 
the hardware compression?) I did this but TSM still only writes about 
37.000 MB on 35/70 GB DLT IV Tape. This is independent from the kind of 
data written (Oracle DBs, Filesystem backups, Domino Data backups, etc.)

Therefor I think, that TSM does not use the hardware compression at all.

TIA

Bernd