topic Re: needed Information about Zombie processes in Operating System - HP-UX

needed Information about Zombie processes

Yashodhan Deo — Thu, 24 Jun 2004 00:58:04 GMT

when I run the top command I see 1 Zombie processes. What are these processes. How do they get created. Are they harmful to the server. Even after rebooting the server the proess remains. I tried using the "ps â ef|grep defunct" command to get more information but I get the following output.

root 22534 2269 0 11:25:37 ? 0:00
root 22559 22536 0 11:26:27 pts/ta 0:00 grep defunct

I am very new to sys admin in HP-UX and also I am using telnet from a system to do my job.
Can any one help as to how can I trace which application is creating the Zomboie process... i.e what is the root cause of Zombie proces

Re: needed Information about Zombie processes

Michael Tully — Thu, 24 Jun 2004 01:07:22 GMT

Is is sometimes a little difficult to trace a zombie's origin unless you take regular snapshots of the process table.

Have a look at this posting for more explanation on zombies.
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=105337

Re: needed Information about Zombie processes

Yashodhan Deo — Thu, 24 Jun 2004 01:39:47 GMT

Hi Michael

Thank u for ur guidance. Can you pls go thro the attached file, basically output of the top, ps command, and try if u can throw more light on the issue. Aslo can we try and findout why even after rebooting the zombie process still exists. Will I have to escalate the problem to product development team.

Thanks in advance.

Yashodhan Deo.

Re: needed Information about Zombie processes

Manish Srivastava — Thu, 24 Jun 2004 01:56:13 GMT

Hi,

After reboot the zombie should go away. If it does not then this is a problem with init(1M). Inint has the responsibility to reap all the zombies.

Zombie itself is not a problem but if you are generating zombies then it is possible that you run out of proc entries.

manish

Re: needed Information about Zombie processes

Franky_1 — Thu, 24 Jun 2004 02:53:08 GMT

Hi,

a process that has exited and has a parent, but has not yet been waited for by the parent, is marked .
Processes that have died but haven't been removed from the process table are zombies.
If you use ps -flp you'll see the "Z" entry under the "S" Header which will indicate the zombie process.

Re: needed Information about Zombie processes

Yashodhan Deo — Thu, 24 Jun 2004 02:57:05 GMT

Thanks guys for guiding me. It added a lot to my knowledge.

Since I am new to the HP-UX administration I have escalated this to my higher ups. Michael I should have given you more points. Consider it 9.

Thank U all.