My comments (below) are AIX-32bit specific.
If Rod is still running on Solaris, there is no need to change.
Wally


Does this mean that I should change my udtconfig parameter to 10485760 * 4
and performance may increase? - Rod


$UDTBIN/ipcstat -mb | grep sbcs
m       8107   0          --rw-r--r--     root    other   10485760  -> sbcs
R6.0
m   37971309   0          --rw-r--r--     root    other   10485760  -> sbcs
R6.0
m    3367268   0          --rw-r--r--     root    other   10485760  -> sbcs
R6.0
m  165791808   0          --rw-r--r--     root    other   10485760  -> sbcs
R6.0


-----Original Message-----
From: Wally Terhune [mailto:[EMAIL PROTECTED]
Sent: Thursday, May 26, 2005 6:02 PM
To: [email protected]
Subject: RE: [U2] udtconfig gurus - AIX shm tuning


AIX doc hasn't been updated (though it is overdue...)
If you read it, don't use AIX extended shared memory - performance issues
with how UniData uses shared memory and how extended shared memory is
implemented by AIX.

We do have a 64-bit port of UniData for AIX (UniData 6.1.7)- which makes
all of the 32-bit shared memory restrictions disappear.

If you are running a 32-bit port of UniData (all the rest) - here is the
short version of tuning to avoid shared memory errors:
1) Set SHM_ATT_ADD=0 (if not already)
2) Tune so you only need one glm segment (record lock table -
GLM_MEM_SEGSZ) ($UDTBIN/ipcstat -mb | grep glm        on a busy system)
3) Tune so you only need one sbcs segment (SBCS_SHM_SIZE)  - depends on how
many application programs you globally catalog
4) SHM_GNPAGES=64, SHM_GPAGESZ=2048 - reasonable place to start. Make sure
pages*pagesz*512 does not exceed 256mb.
5) SHM_LMINENTS=15 (or more - small structure - 30 is OK setting and likely
more than you will ever need).



Wally Terhune
Wally Terhune
Manager - U2 Advanced Technical Services
IBM Information Management Solutions
Tel: 303.294.4866             Fax: 303.294.4832
[EMAIL PROTECTED]

www.ibm.com/software/data/u2/support - Open, Query, Update, Search -
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