UNIX for Dummies Questions & Answers

I have some zombie's in my env , i have no idea from where they created
but how can i kill them ?
How can i know what is the source of the zombie process?

In UNIX every parent process is responsible for cleaning up after his child processes. As when process is done, its parent process removes it from the system properly and clean its data structure. Sometimes parent process is getting killed or terminated before his child process ends. In such case child process has to be terminated by INIT process. Unfortunately it not always does it clean or perfect.
Zombie processes aren't the real, because there's is no "process" in the execution queue and only some data structure still persist. If they are few just disregard them, as zombi is a normal phase (undesirable but normal) of process's lifetime. If there are many, the only real way to get rid of them is to reboot the system The command "kill", even with -9 wouldn't help as process had been eliminated already.
Get "UNIX Essentials and UNIX Core" DVD as it explains stuff like that.

Hope it helps.

To clean up zombies, use the following procedure:
1. Run 'ps -ef|grep defun' to search for defunct processes
2. Check the parent process for the zombies
3. See if the parent can be killed. If it can be, kill it.
Once you kill the parent, then all its children (zombie) processes will be inherited by init. Init will immediately wait for all the pending children and that will be the end of the zombie processes.

Note that if you have several different parent processes that have zombie children, you have to kill all those processes.

Hello and tnx for the fast reply
i have question , how can i find out who is the defunct parent process ?
say if i got :
mydir 28138 9186 0 1:51 <defunct>
after runing 'ps -ef|grep defun'

tnx

in your case:

9186 is the Parent PID(PPID), to display parent process and all its child processes you could do: replace 9186 with your PPID. Hope it helps!