However, if you have high-capacity tape, you don't have to spend a whole
tape for each node.  You can control the tape use by setting a MAXSCRATCH
value for the tape pool.  For example, if you have 200 clients to back up
and you set MAXSCRATCH to 100, TSM will put two clients on each tape.  You
get all the benefits of colocation, without having to spend too much extra
tape.

Regarding your configuration:  we back up every form Windows, plus AIX, SUN,
IRIX, Mac, OS/2 -  all into the same 60 GB disk pool and same tape pools.
OVer 500 clients, and there has NEVER been any type of problem from mixing
this data in the pools or on the tapes.

If you give up your disk pool and go direct to tape, you will lose a lot of
the flexibility that TSM provides and have to do a lot of extra scheduling
for your client backups that TSM would normally handle automatically for
you.

If you split your clients into separate disk and tape pools, you will also
be losing a lot of flexibility and creating yourself a lot of extra
management work, all for no real benefits.

Don't try to make TSM work like another product.  It was designed this way
for a reason.
My opinion, take it or leave it...

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Wanda Prather
The Johns Hopkins Applied Physics Lab
443-778-8769
wanda_prather AT jhuapl DOT edu

"Intelligence has much less practical application than you'd think" -
Scott Adams/Dilbert
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