A zombie process doesn't react to signals because it's not really a process at all. A zombie is already dead. Therefore it cannot be killed. ;-)

If you want too kill the parent process of zombie process then do the following:

ps xal | grep '[z]ombie' The third field on each line is the parent pid. then use normal kill command for that.

http://forums.cpanel.net/f5/how-kill-zombie-process-server-62738.html