How do I enable hardware compression on a drive?

[Robert G. Fisher]

I'm running multiple SCSI DDS-2 and IDE TR-3's on various linux
machines and using tar for backups, but I'm unclear on how I
can turn on hardware compression to fit more onto the tape.

Since I'm using tar, I don't want to use the -z option since
if there's a problem, I lose my entire backup obviously.

-- 
Robert G. Fisher                     NEOCOM Microspecialists Inc. 
System Administrator/Programmer      (540) 666-9533 x 116