Our tsm runs on a p550 with 4 processors and 8 GB of memory running Aix 5.3.  
The DB is 131,072 MB and is 64% utilized.  Bufpoolsize is 1024 MB.  Expirations 
average around 3 hours.

>>> Zoltan Forray/AC/VCU <zforray AT VCU DOT EDU> 4/28/2008 10:41 AM >>>
Pertaining to the recent discussion of buffpool sizing (larger vs smaller
- cpu usage, etc) I would like to get some opinions.

I followed the discussion and was aware of the issue of going too large
and killing any benefits by increased CPU usage and such.

So, I have been experimenting.

My big Linux TSM server has 8GB RAM and is dedicated to TSM, so other
products using/sharing the memory is not an issue.  The TSM DB is 160GB
assigned with 77% used.

The buffpoolsize (with selftune) was set to 768MB.

I just bumped it to 1GB (still at the 1/8 of real memory guideline) to see
if it would improve things, using EXPIRE INVENTORY as a benchmark and
trying to ignore the "Cache hit%" value (which I could never keep at or
above 99%).

Before the change, I was seeing EXPIRE INVENTORY running 46-51 hours.

This past weekend, it ran 40H.

I realize that having only 1-test result after the change is hardly a good
indicator of either positive or negative results.

So, my question is this.

Do I bump it to 1.25-1.5GB (still well below the "guidelines" of 1/8-1/2
of real memory) and see if that improves things even more or do I drop
down to 512MB to see if it improves things even more than the memory
increase?

Anyone else willing to share their DB sizes/buffpool/expire inventory
durations?

Open to all thoughts (besides the need for another TSM server......this is
already in the works and we have stopped adding new nodes to this server).