topic configuration of shared memory .. in Operating System - Tru64 Unix

configuration of shared memory ..

Siddhartha Das — Wed, 31 Aug 2005 02:09:25 GMT

Following things has been done from my end ..

1) /sbin/sysconfig -r ipc shm_max=33554432

2) Changed the value from CDE Karnel tuner.

3) added on sysconfigdb also.

Quary :

1) /sbin/sysconfig -s shm_max
shm_max:loaded and configured

2) /sbin/sysconfig -q ipc shm_max
showing 33554432

Now if I run ipcs then it is not showing any shared memory.

but if I run /usr/field/shmx -m 33554432 and then run ipcs it is showing shared memory segments.

What needs to be done to automatically run the process during boottime.

Re: configuration of shared memory ..

Han Pilmeyer — Wed, 31 Aug 2005 03:00:58 GMT

You have just taken all the necessary steps to allow the maximum size of a shared memory segment to be increased to 33554432(32 MB). However you haven't actually allocated any segments. This is up to an application to do that. The shmx program is a shared memory exercisor that will allocate such a segment for the duration of its run.

Re: configuration of shared memory ..

Ivan Ferreira — Wed, 31 Aug 2005 08:34:39 GMT

Yes, after setting the shared memory parameters, the application will then create the shared memory segment.

But, isn't too low your shared memory configuration?

For oracle, the default shared memory is 2GB and can be increased to 4GB-16M. It depends also of the available memory on your system.

Re: configuration of shared memory ..

Hein van den Heuvel — Wed, 31 Aug 2005 10:05:56 GMT

Just echoing what has been said before:

You have taken all the rigth steps to allow for a 32M shm section to be created by an application, but it is still op to the application to create it wih shmget.

field/smhx is amn excerciser (try with -h) and will create a shm section, but just for its own use and only during its own time

What is your application?
32M seem a little low for shmmax.
I am used to 2GB give or take 8mb.

If you use Oracle, you may want to run $ORACLE_HOME/bin/maxmem

If you use SAP then you may want to run:
$DIR_LIBRARY/memlimits

hth,
Hein.