Bill,

I made this change a while back without any real problems. I just enabled
collocation. It took some time but eventually my tapepool became
collocated. Also, TSM shouldn't crash because it ran out of scratch tapes.
Remember, if TSM runs out of scratch tapes it will find the least used tape
and write on it. You loose collocation on that tape but TSM continues on. I
can think of only two situations that running out of scratch tapes would be
a major problem, 1-when a database backup is needed and 2-every tape in the
storage pool has become full. With a little planning and monitoring you
should be able to detect and take corrective action before TSM dies.

Also, if your drive mount retention is set to high you'll have a bunch of
idle tape drives. Remember, collocation will force a mount of at least one
tape for each node. So, make sure that you don't use the default of 60
minutes. Cut it back to say 5 minutes so that the drives will be freed up
quickly.

Rick Saylor
Austin Community College

At 11:22 AM 7/29/2003 -0400, you wrote

Hi TSM'ers

      Has anybody out there gone from 3 years of nocollocation and then
changed to collocation for better restores.  We are currently at 2-3+ TB of
info on 540 tapes (this is all in our 1 TAPEPOOL).  We have about 410
scratch tapes and the uppers are worried about making the global switch to
collocate will cause TSM to crash due to no scratch tapes.  Also if there
are any other gotcha's I would be greatly appreciated.  Maybe even send
you, some of our greatest pizza haha.

Thank You,
Bill Rosette
Data Center/IS/Papa Johns International
WWJD

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Rick Saylor                Austin Community College   Voice: (512)223-1182
Senior Systems Programmer  9101 Tuscany Way           Fax:   (512)223-1211
Information Services       Austin, Texas  78754