shmmax and oracle sga

[Heidi Miller]

We are currently running oracle 9.2.0.5, hp-ux 11.11i. We have 28G of physical memory on an rp8400. Currently the shmmax kernel parm is set at 2G. I would like to increase but am not sure by how much. The current size of the SGA is just under 4G. Also, if I increase the shmmax are there any additional parms that should be increased along with it?

[Chan 007 · Accepted solution]

Please see the link about all the KP and their use

http://docs.hp.com/en/939/KCParms/KCparams.OverviewAll.html

Also I recon check wuth Oracle

Chan

[Court Campbell]

In my personal opinion you should set shmmax to a little greater than the size of the sga. This way the sga will fit in one shared memory segment. In your current case it would be using 2 shared memory segments to hold the sga. take a look at this:

http://orafaq.com/node/8

check out the section titled SHARED MEMORY ALLOCATION.

[Court Campbell]

P.S. Oracle recommends setting shmmax to the size of available physical memory. That is just ridiculous.

[Court Campbell]

Please assign points if we were able to help you.

https://community.hpe.com/t5/Community-FAQ/FAQ-Kudos/td-p/6838486