topic Re: defunct process in Operating System - HP-UX

defunct process

navin — Mon, 22 Sep 2008 16:06:55 GMT

I have couple of defunct processes that appears in the pa risc server .which runs 11.23
I would like to is there a simple way to find out which process or script causing this .
thanks in advance

Re: defunct process

James R. Ferguson — Mon, 22 Sep 2008 16:17:44 GMT

Hi:

Defunct processes are processes for which the parent has not yet reaped the dead child's status. You can find "defunct" processes by with:

# ps -ef|grep defunct

or:

# UNIX95= ps -o pid,state

...and looking for pids with a "Z" state.

A process is also called a 'zombie'. It is already dead, waiting for its parent to reap its termination status before it is removed from the kernel's process table.

Regards!

...JRF...

Re: defunct process

Kenan Erdey — Mon, 22 Sep 2008 16:22:43 GMT

Hi,

find processes ps -ef | grep defunct. And find the process by looking for the parent process' id. this may help you.

Kenan.

Re: defunct process

navin — Mon, 22 Sep 2008 16:24:47 GMT

Thanks Much .By removing ppid the defunct process will be terminted completely.But other than th ebad code..what could be the cause for these in general.
Thanks much

Re: defunct process

Jeeshan — Mon, 22 Sep 2008 16:34:35 GMT

'defunct' processes only take up an entry in the process or ps table and exist due to poor programming clean up.

These are processes whose parents have vanished without a syscall of wait() or waitpid() to collect the exit code of these children and remove them from the process table.
If you have lots of these zombies this is usually a sign of a piece of badly written code that produced them.
though they don't take up resources they are to avoid because they fill up your process table and can result in a system that cannot fork new processes, and thus is forced to be rebooted.

Re: defunct process

Torsten. — Mon, 22 Sep 2008 16:36:40 GMT

For some (diagnostic related) processes this is expected behaviour - what is the name of your processes?

Re: defunct process

Dennis Handly — Mon, 22 Sep 2008 17:37:20 GMT

>ahsan: These are processes whose parents have

No, these zombie masters are still there. If they were dead, init would reap them.

>Torsten: For some (diagnostic related) processes this is expected behaviour

Well, more of a known problem than expected. :-)

Re: defunct process

Torsten. — Mon, 22 Sep 2008 17:46:42 GMT

Well, I agree.

There was a problem with ia64_corehw, IIRC.