topic Re: semaphore setting in Operating System - HP-UX

semaphore setting

O'lnes — Mon, 11 Nov 2002 07:30:19 GMT

When starting the db on the unix system it pop up some db error ???
without enough semaphores available to .....???

it suggests to increase the semvmx , how can i change the semaphore setting ? How can I know the memory usage
status eg. Free , using etc? thx

Re: semaphore setting

Elif Gius — Mon, 11 Nov 2002 07:33:50 GMT

Hi,

# ipcs
...then you see the semaphores and shared memory which is used

You can increase the semaphore settings with sam ... Kernel Configuration ... Configurable Parameters...
then a new kernel will be created

Re: semaphore setting

Juan Manuel López — Mon, 11 Nov 2002 09:27:16 GMT

" ipcs " to get the semaphores status.
To increase the max. Semaphores, try to make it from sam, configurable parameters.
To know the memory usage, use " swapinfo ".

I hope this can help you.

Juanma.

Re: semaphore setting

O'lnes — Mon, 11 Nov 2002 10:10:15 GMT

I chceked by the comamnd " swapinfo" that the memory usage is very high - over 90 % , except reboot the machice , how can I lower it ? thx.

Re: semaphore setting

Juan Manuel López — Mon, 11 Nov 2002 10:26:55 GMT

On my system the memory usage is:

dev 4194304 28504 4165800 1% 0 - 1 /dev/vg00/lvol2
reserve - 1818168 -1818168
memory 3153576 2691060 462516 85%

The important data from this command is the memory on " dev " ( swap memory ). If you have a lot of this memory ussage, you have a problem. It is that your case ?.

Juanma.

Re: semaphore setting

Juan Manuel López — Mon, 11 Nov 2002 10:32:17 GMT

O??Ines, do not forget to give us points.
Thanks.

Juanma.

Re: semaphore setting

T G Manikandan — Mon, 11 Nov 2002 10:34:39 GMT

Just use glance to find out the processes using more memory.
you can also identify the processes and their memory usage using

#UNIX95= ps -e -o ruser,pid,vsz=Kbytes|more

What are the values for the parameters semmns semmni and semvmx in kernel?

Thanks

Re: semaphore setting

O'lnes — Tue, 12 Nov 2002 11:56:50 GMT

the below is the output of 'ipcs -a'

s 49 0x00000000 --ra-ra-ra- root sys root sys 24 1
6:17:00 16:16:57

how can i know the how many memory is used in this process, how to optimize the memory? thx.

Re: semaphore setting

O'lnes — Tue, 12 Nov 2002 12:04:25 GMT

if there are too many files opend in our system , how can I delete open files to release the memory, except reboot the UNIX , is there any other method? thx.

Re: semaphore setting

T G Manikandan — Tue, 12 Nov 2002 12:26:35 GMT

#ulimit -aS

To find the value of number o f open files limit.

you can increase it by using

/usr/bin/ulimit -Sn 1000

This will increase the maxfiles to 1000.

Also you can do this using the kernel by increasing the parameter

maxfiles ---->This is the soft limit for open files

maxfiles_lim--->This is the hard limit for the open files.

Thanks