Is there a way to identify which process turns into Zombie process

Question

One of the ubuntu server has 82 zombie processes. All processes shows '[sh] defunct' as process command. Is there a way to find out which process is becoming a zombie process?

I tried checking the /proc/PID/ directory to get some clue about zombie process but all files are empty. How to find who let this process as zombie.. . Is there any other way to find it out?

Updated/Solved: Made the question clearer, and Answered my own question as suggested by andcoz.

Answer 1

Of course you can. There's many ways to do it, most common is probably :

ps aux

You can add a basic | grep -w Z and you'll have a short list of your zombies. If you only want a list of zombie process and their pids, you can do as indicated on this page :

ps aux | awk '{ print $8 " " $2 }' | grep -w Z

Check this question for more details about process information.

Answer 2

The short answer is that you don't care. A zombie process is dead. All it consumes is a tiny bit of kernel memory, for that entry in the process table.

Since all that remains of the process is the process table entry, you have little to go on. A zombie process is a dead process that its parent hasn't reaped yet; look at the process's PPID to see who the parent is.

Answer 3

One of the reasons for Zombie process are 'parent process' not waiting for the 'child process' - Executed ps -l which shows the parent process ID, with that you can find exactly which process is responsible for zombies in the machine.