Simpler Navigation for Servers and Operating Systems - Please Update Your Bookmarks
Completed: a much simpler Servers and Operating Systems section of the Community. We combined many of the older boards, so you won't have to click through so many levels to get at the information you need. Check the consolidated boards here as many sub-forums are now single boards.
If you have bookmarked forums or discussion boards in Servers and Operating Systems, we suggest you check and update them as needed.
Operating System - Tru64 Unix
Showing results for 
Search instead for 
Did you mean: 

reconfigure the kernel


reconfigure the kernel

Hi everyone

I am using tru64 unix and I want to know how to Reconfigure the kernel to have bigger segments

Martin Moore

Re: reconfigure the kernel

First question: do you mean shared memory segments? I'll assume so for the rest of this answer.

Second: what version of Tru64 are you using?

To increase the maximum shared memory segment size (the default is 4 MB), you need to define a new value for parameter shm-max (if V4) or shm_max (if V5) in /etc/sysconfigtab and reboot. This parameter is in the ipc subsystem. So you'd find the ipc: stanza in /etc/sysconfigtab (or add one if it doesn't already exist) and add a line like this:

shm_max = 8388608 (this would double the size to 8 MB).

If there is already a definition in shm_max, replace the existing value with your new one.

For V4, the maximum allowable size is 2 GB minus 1 byte, but for performance reasons it's a little better to use an exact multiple of 8 MB, so you could use up to 2 GB minus 8 MB.

For V5, the maximum allowable size is 18 exabytes or so, which is far larger than can be practically used, so it's effectively unlimited.

I work for HP
A quick resolution to technical issues for your HP Enterprise products is just a click away HP Support Center Knowledge-base
See Self Help Post for more details