topic Re: Zombie question in Operating System - HP-UX

Zombie question

Peter Gillis — Sun, 28 Sep 2003 18:44:32 GMT

HI,
HPUX 11.00. RP2450.
Would someone please advise on method to trace origin of zombies? Have issued top cmd and see 1 zombie.
Thanks,
Maria.

Re: Zombie question

Michael Tully — Sun, 28 Sep 2003 19:21:01 GMT

Hi Maria,

Have a look at this posting.

http://forums1.itrc.hp.com/service/forums/parseCurl.do?CURL=%2Fcm%2FQuestionAnswer%2F1%2C%2C0x1899afe90f1cd71190050090279cd0f9%2C00.html&admit=716493758+1064794789026+28353475

Cheers
Michael

Re: Zombie question

Con O'Kelly — Sun, 28 Sep 2003 19:24:48 GMT

Hi Maria

Try using
# ps -ef | grep defunct.

Look at the PPID (Parent Process ID), it might give you a clue as to what application the process is from, though often with zombie processes the PPID is 1.

You will probably have difficulty getting rid of this zombie process unless you re-boot. Sometimes its possible to get rid of them by killing the Parent Process but NOT if PPID is 1.

Cheers
Con

Re: Zombie question

Peter Gillis — Sun, 28 Sep 2003 19:38:56 GMT

Thankyou, for your help. Have established where the zombie originated, and how i can now attempt removal of it.
Maria.

Re: Zombie question

Umapathy S — Mon, 29 Sep 2003 03:49:42 GMT

Maria,
Once processes go into the zombie/defunct state, it is hard to remove them. Many times you have to reboot the machine to clear them off. Check those applications which created zombie for correct programming practices.

HTH,
Umapathy

Re: Zombie question

Mark Grant — Mon, 29 Sep 2003 06:07:04 GMT

Maria,

Please be aware that your zombie is not causing you any trouble. The only thing it is using up is one process slot and you probably have enough of them.

Having said this, if you have found the process that creates the zombie, you might try sending it a signal 15. This might persuade it to clean up after it.

Re: Zombie question

Keith Bevan_1 — Mon, 29 Sep 2003 10:25:12 GMT

Maria,

Following on from Mark's reply, if this signal 15 fails then you could try the harsh signal 9

Keith

Re: Zombie question

A. Clay Stephenson — Mon, 29 Sep 2003 11:00:51 GMT

NOTE: A zombie process is already dead; you can't kill it. You can send it signals (even kill -9's) till the cows come home and it will still be dead. The zombie does no harm and all processes go through the zombie state. The only real cure is a reboot and for the loss of one entry in the proc table it just ain't worth it.