Brag.....brag.....brag..................................;--)))

Yes, we fully realize that an AIX box would have been leaps
faster............It just wasn't going to happen. AIX is being phased out
completely.  Our direction is Solaris (no, not for TSM......) Linux and
Windoze......




David E Ehresman <deehre01 AT LOUISVILLE DOT EDU>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
04/28/2008 01:28 PM
Please respond to
"ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>


To
ADSM-L AT VM.MARIST DOT EDU
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Subject
Re: [ADSM-L] DB Bufferpool sizing - continued






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).