From: Richard Sims [mailto:rbs AT BU DOT EDU] 
>>TSM doesn't use hardware compression. Whether or not a tape drive uses
>>compression is a parameter set at the operating system level.
>
>TSM certainly sets the drive attributes to effect hardware compression.
>The 'C' at the end of the DEVclass FORMAT spec incites the server to
>set that drive attribute.  In AIX, the drive attributes 
>currently in effect
>can be listed via 'lsattr -EHl rmt1'.  Solaris must have 
>something similar, but that's beyond my experience.

Apologies. The device class definition can tell TSM that compression is
to be used on a given tape drive(s). However, compression must be turned
on at the OS level before the device class definition can be used. I'm
sure that Solaris has a setting to turn compression on, just as AIX
does, but, like Richard, it is also beyond my experience.
 
--
Mark Stapleton (mark.stapleton AT berbee DOT com)
Berbee Information Networks
Office 262.521.5627