Shared Memory settings

[DZH]

Hello everyone! I'm trying to make some changes to the IPCS settings on my machine, and I would do better with some help. I have the current settings on Solaris 8:

4294967295 max shared memory segment size (SHMMAX)
1 min shared memory segment size (SHMMIN)
32767 shared memory identifiers (SHMMNI)
32767 max attached shm segments per process (SHMSEG)


What I want to know is whether the above values, SHMMAX, SHMMIN, SHMMNI and SHMSEG are related in some special way. Secondly, I would be grateful for any information pertaining to advantages and disadvantages of setting the above parameters to a given value.

 

[Annihilannic]

They are related in that they all pertain to shared memory. You shouldn't need to change these unless an application specifically requires more of them, especially as they seem to be set to fairly generous values already. Annihilannic.

 

[dobbyn]

Your values for shmmax and shmseg are already set to the maximum allowed value. The value for shmmni (number of shared memory identifiers) can be set as high as 2147483648 (2GB).

The main effect of setting these values too high is that you are using more kernel memory than necessary. If you set them too low, your applications may not run.