Hi sreekumar,

you was right in setting bufpool as high as possible.
You do not mention plattform/version of you server.
I was told by IBM that in latest NT TSM Server versions there are no
limits for bufpoolsize
exept for usable free system memory (free RAM).
If TSM is the only application running on the machine you simply can
test
a Bufpoolsize usin whole memory minus OS ant ADSM code size.

You surely restart TSM after having bufpoolsize changed, do you?

With 3.1 and 3.7 I had very good results with HW upgrade: 
splitting the DB acros 3 small raid1 arrays
and using a scsi controller with 128 on-board cache.

To my surprise the caching on controller seemed to 
work better than the one of TSM itself,
so using the max. bufpoolsize of DSM 3.1 which was, I believe, 128 MB,
consequently reaching cache hit of about 97% only,
was no problem at all (having DB as large as 9 GB ).

regards

Juraj SALAK
Asamer & Hufnagl