Hi All,

Recently i have a problem with installing OVO (openview operation). I can't seem to install it due to semaphores insufficiency.This is a RHEL3 box.
I have increased the semaphores from 250 to 2500, but i didn't reboot the server.I have just edited the /etc/sysctl.conf (#Semaphore increase to 512
kernel.sem = 2500 32000 32 512).

And yet i am experiencing this semaphores problem. I see the Squid & Apache is taking alot of memory, but the swap is OK.

How can i make the semaphores utilization to normal so i can proceed with OVO installation?

Hello and Welcome to LinuxQuestions,

If you've changed the sysctl.conf file you'll need to reload the settings in order to apply them (or reboot which should only be a last resort). Have a look at the man page for sysctl:
which will tell you that you have to run sysctl with the -p option to apply your changes. And you do know that you're running a VERY old version of RHEL, right? That version is no longer supported, and hasn't been for years so you're missing out on lots of updates both system and security. Any particular reason to use such an old version? Have fun with Linux.

Kind regards,

Eric

Hi Eric,

I have updated the new semaphore values by running sysctl -p and the new value is reflected when i check using the command below;

[root@somebox bin]# /sbin/sysctl -a|grep -i sem
kernel.sem = 2500 32000 32 512

i didn't reboot however. this server is my customer server and there is nothing i can do about it to migrate to RHEL4 or 5. haha!

how can i check if the semaphores are being exhausted by squid or httpd?

Hello,

No personal experience with that on my side, but I've found these links which might be of help while you wait for another more experienced LQ user to chip in.

Semaphores in Linux
semctl manpage

Kind regards,

Eric

1 members found this post helpful.

Thanks Eric...i will look in to those site.

THis semaphore thinggy is really frustrating.. sighhh...