defunct , zombie processes

[Ali Sunderji]

I need to kill quite a few defunct processes but kill -9 process# does not do the
trick.

I know there is a way I could resolve this by using and init command followed by kill HUP.

I am not sure of the syntax.

assistance or any other suggestions would be welcom.

THX

[Ross Zubritski]

If -9 isn't killing the processes, a bounce is about all you can do.

You should only use -9 as a last resort.

Regards,

RZ

[Jeff Schussele]

Hi Ali,

It's like the old joke, "How do you kill the already dead"?
You can't....

If their PPID (Parent Process ID) is NOT 1, then you may be able to remove them by killing the parent.
If their PPID is already 1, then there's nothing you can do short of a reboot. If they're using no or little CPU time, then they're no threat. IF they ARE using modest/high CPU time then you may be forced to reboot.

HTH,
Jeff

[S.K. Chan]

The init (init s) you're talking about it probably bringing it down to single user mode and then killing it from there. That should work but reboot it cleaner. These processes usually do not affect the system performance, so you may want to wait until you have that window available for you to reboot it.

[Michael Steele_2]

defunct processes that have gone to init don't consume any resources 99% of the time. That wasn't always the case so the legend remains.

Usually they're associated to I/O in someway. Often its a ksh / user whose ungracefully left his rlogin or telnet session.

But if they're associated to an application or process its time to get on the horn to the developer and make sure they clean this bug up.

To be sure about any resource usage:

lsof -p pid
ipcs | grep process
top | grep process