>what are the implications on doing this?
>I saw on the Redbooks that this is not recommended!

Data compression is not always benign...  Trying to compress
already-compressed data can actually cause it to increase in size.
Ideally, you only want to compress data once.  In reality, it may
be beyond your control, as some facility on the client system may
have compressed it before TSM or the tape drive get it.  In
general, avoid knowingly causing multiple compression operations:
have either the TSM client do it, or the tape drive, but not both.

  Richard Sims