topic Re: Semaphores in Operating System - HP-UX

Semaphores

Gary Stewart_3 — Thu, 23 Mar 2000 05:41:31 GMT

I am running Diagnostics on a V2500 running HPUX 11.0. Early this morning the
syslog recorded the following error;
diagmond[11744]: Exit due to semaphore failure

Can anyone help me determine the cause of this? I need diagnostics to run
continously. THanks.

Re: Semaphores

Chris Anoruo_1 — Thu, 23 Mar 2000 06:53:29 GMT

HI GARY,

YOU HAVE TO CHECK THE VALUES OF YOUR SEMVMX AND ALL THE OTHER SEM*** IN YOUR
KERNEL CONFIGURATION FILE.
eg: SEMVMX=32767.

Cheers!

Re: Semaphores

Charles Yates — Thu, 23 Mar 2000 06:59:40 GMT

I work with Gary.
Currently, the kernel parameters for semaphores are:
sema 1
semaem 16384
semmap 3074
semmni 3072
semmns 16384
semmnu 2048
semume 2048
semvmx 32767

Re: Semaphores

Chris Anoruo_1 — Thu, 23 Mar 2000 08:10:33 GMT

Hi charles,

Use the 'ipcs -mobs' command to add up the values of NSEMS at your system peak
time. With this you should be able to know the value to set your SEMMNS.

May I suggest you reduce the following values to:
SEMMAP=2048
SEMMNI=2046
SEMMNS=8192
SEMMNU=2048
SEMUME=1024

This will definitely require a system reboot.

Re: Semaphores

Charles Yates — Thu, 23 Mar 2000 09:40:09 GMT

Thanks, Chris, but why would I want to reduce those values? Also, FYI, we have
3 other V2500s configured the exact same with no problems. Also, in the
syslog, I found this entry:
Mar 23 04:30:50 LVM[20748]: /usr/lbin/lvlnboot -v
Mar 23 04:30:54 diagmond[11744]: Exit due to semaphore failure

We have HAO which seems to be running the lvlnboot commands, as well as other
stuff, early in the AM.