The approach is valid and can reap significant backup/restore time benefits for 
the clients.
Two points:

                1) No new licensing cost are involved.  TSM is licensed by the 
environment, not the number of TSM servers.
                 
                2) Consider the complexity of resources scheduling between many 
servers.  Most sites have a limited number of tape drives and contention can be 
a bear to schedule out with so many independent servers and their separate 
schedulers.  An external admin scheduling utility may be needed.

 
Orville L. Lantto
Glasshouse Technologies, Inc.
 
 

________________________________

From: ADSM: Dist Stor Manager on behalf of Robin Sharpe
Sent: Mon 3/13/2006 11:03 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: [ADSM-L]



Dear colleagues,

It's time for us to split our TSM into several new instances because our
database is now just too large -- 509GB -- and still growing.  My initial
plan is to create five TSMs - four plus a library manager - on the existing
server (an 8-way, 12GB HP rp7410 with 15 PCI slots).  This is cost
effective since no additional hardware or license is needed - just lots of
SAN disk for the databases, which we have available.  But, I've been
thinking.... what do you think about the following:

A more "creative" approach is to place the "new" TSM servers on existing
large clients.  This has several advantages:
-     eliminates need to acquire new servers, saving physical room, power
and cooling requirements, additional maintenance.
-     client benefits by sending its backup to local disk using shared
memory protocol. Eliminates potential network bottleneck.
-     Client sends data to tapes using library sharing; no need for storage
agent.
-     Use of local disk eliminates the need for SANergy
-     heavy clients "pay" for their usage by providing backup services for
smaller clients.

There are also some concerns (not necessarily disadvantages):
-     May require CPU, memory, and/or I/O upgrades (still cheaper than
buying a server)
-     TSM operation may impact client's primary app.  Can be controlled by
PRM on HP-UX.
-     Incurs licensing cost.

Thanks for any insights....
Robin Sharpe
Berlex Labs