We were using 3480 uncompressed, with client compression - we turned on IDRC
and saw nothing.  The reason for this is that ADSM reports such as Q VOL
report the actual amount of data written to the device.  For example - if you
have 25M of real data, and ADSM compresses it to 10M, then Q VOL will show
10M.

Jerry Lawson
jlawson AT itthartford DOT com
________________________Forward Header________________________
Author: INTERNET.OWNERAD
Subject: Re: 3590 Compression
01-30-97 12:51 PM

Use

update devc xxx devt=3590 format=3590C estcap=13g
or
update devc xxx devt=3590 format=drive

Note that this will only have effect on tapes that you start to fill after the
update. You will need to perform move data, tape reclaim,... to get more stuff
on the already used tapes.

To check: q vol of *FULL* tapes will tell you how much data you have really
managed to squeeze in.

On Jan 30, 11:50am, Aughenbaugh, William wrote:
<=> Subject: 3590 Compression
<=>We have a silo w/ 3590 tapes(10gig).  its filling up pretty quick.  Does
<=>anyone know how to activate the compression feature which changes the dev
<=>class to 3590C.  and how do you check its actually working. theoretically
<=>were supposed to be able to have up 25gig on one tape.  Does it affect
<=>the current storage pools that contain data or just newly added tapes?
<=>has anyone sucessfully done this?
<=>
<=>Thanks for your help in advance!
<=>
<=>Bill Aughenbaugh
<=>Moodys investor Service
<=>Aughenbw AT moodys DOT com
<=> End of excerpt from Aughenbaugh, William



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