Ken & others,

You modify it in the DSMSERV.OPT file which gets read when you start
the ADSM server, so if you change it you must restart for the update to
take effect.

You can find recommended settings in the new V3 Performance tuning Guide

http://www.storage.ibm.com/software/adsm/pfguide/tgv31mst.htm

We have followed this guide & set it at 32768 (for 256MB system) and we
are averaging 98%.  We will soon try to bump it up a bit by upping this
parameter a bit.

I suspect you are using default of 2048 to get % so low (which is what
we had up till recently!).

Good luck.

Simon


----------
| From: ADSM-L AT VM.MARIST DOT EDU; ken.chamberlain AT UTORONTO DOT CA
| From: ADSM-L AT VM.MARIST DOT EDU; ken.chamberlain AT UTORONTO DOT CA
| To: ADSM-L AT VM.MARIST DOT EDU
| Subject: ADSM performance
| Date: Friday, 23 October, 1998 2:24AM
|
| Another question...
|
| I've seen recommendations in this list forum advising ADSM administrators to
| run the ADSM server with a large enough buffer pool so that cache hit
| percentage is about 98%.  When I issue "q db f=d" it reports:
|
|              Buffer Pool Pages: 128
|          Total Buffer Requests: 354,376,322
|                 Cache Hit Pct.: 89.48
|                Cache Wait Pct.: 0.00
|
| So I guess we're a little low on buffer pool, and I've noticed daily copy
| pool processing and disk to tape migration is taking longer and longer.
| I've asked our unix support guy to look into upping buffer pool, but he's
| come back with "How?".  So my question is: How/where do we specify buffer
| pool size?  "q db f=d" reports it at 128 pages but where do we specify 128
| pages?  This must be a default.
|
| Ken Chamberlain
| University of Toronto
| Phone:(416) 978-1582
| Fax:  (416) 971-2085
| E-mail: ken.chamberlain AT utoronto DOT ca
|