topic User process in Operating System - Linux

User process

peterchu — Wed, 21 Apr 2004 21:51:35 GMT

I have a RH linux server and create a user id for batch job processing , I found that sometimes there are many dead processes on the system , then other process can't be run , does linux limit the no. of process that the user id can run ? thx

Re: User process

Steven E. Protter — Wed, 21 Apr 2004 22:03:03 GMT

Do you mean dead processes or zombies?

I know of no limit on the number of processes a single user id can start. I'd like to see some ps -ef data on the processes to start.

Unix in general has a limit called nproc which is an overall number of processes allowed.

You should also look at the batch jobs being spawned for obvious shell or other programming problems causing this.

SEP

Re: User process

Martin P.J. Zinser — Wed, 21 Apr 2004 22:04:02 GMT

Hello,

yes it does ;-) Run ulimit -a with this userid and you will see the current settings. This can be configured in /etc/scurity/limits.conf .

For a longer discussion check

http://www.linux.com/howtos/Xterminals/advanced.shtml

Greetings, Martin

Re: User process

peterchu — Wed, 21 Apr 2004 23:10:42 GMT

thx replies,

I tried ulimit -a, but still have qustion

is "open file = 1024 " mean only 1024 files can be open at the same time ?

is "max user processes = 7168" mean only 7168 processes can be run at the same time ? thx

Re: User process

Roberto Polli — Thu, 22 Apr 2004 03:01:39 GMT

Hi all,
yes, it tells you the max nr of processes a user can have.
you can limit cputime too and other stuff.

Check
# info bash
and the search for ulimit using
/ulimit [enter]
and then press "n" untill you find it.

Peace, R.

Re: User process

Yu Wang_1 — Fri, 23 Apr 2004 09:20:21 GMT

You can also set soft limit and hard limit. For instance,

soft nproc 32
hard nproc 64

Which generally gives users max process number limit 32 but if someone needs more they can raise the limit per session up to the hard limit (64).

Yu

Re: User process

Bill Thorsteinson — Fri, 23 Apr 2004 09:58:18 GMT

You can configure the limits in /etc/security/limits.conf.
PAM will use this to configure the limits when it validates the processes.
Red Hat may have the limits.conf in another directory.

Re: User process

Yong_7 — Fri, 23 Apr 2004 13:11:55 GMT

Hi,

surely, there is such limit there as same as other *NIX. but lift that process limit bar won't fix the problem.

see here for your choices

http://www.linuxsa.org.au/tips/zombies.html

and may need look at OS patch or your batch shell scripts too to address root cause.

Cheers !

YJ