Best way to kill Zombie and D state processes in linux

Question

What is the best way to kill Zombie processes and D state process by single command.

Solution 1

Double tap.

Actually, reboot. There's no real way to easily get rid of a zombie, but there's really no reason to because a zombie isn't taking up resources on the computer; it's an orphaned entry in a process table. Init is supposed to collect it but something went wrong with the process. http://en.wikipedia.org/wiki/Zombie_process

Perhaps you're asking because there's worse problem...are you getting a boatload of zombies roaming your process table? That usually means a bug in the program or a problem with a configuration. You shouldn't have a huge number of zombies on the system. One or two I don't worry. If you have fifty of them from Apache or some other daemon, you probably have a problem. But that's not directly related to your question...

Solution 2

/sbin/reboot

You can't kill a zombie - its already dead

If the ppid still exists, then terminating that can often clean up the spawned zombies.

You shouldn't be killing processes in uninterruptible sleep - usually this means they're i/o bound, but IIRC it can also occur during a blocking read from e.g. a network socket.

Solution 3

Errors in underlying filesystem or disks might cause I/O bound processes. In this case try to "umount -f" the filesystem they depend upon - this will abort whatever outstanding I/O requests there are open.

Solution 4

Next line will kill all zombies

ps -xal | grep defunct | awk '{ system (" kill -9 " $4 ) }'

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Comments

[lepe]

Related: unix.stackexchange.com/questions/5642/…

[vnix27]

there are around 10 zombie process

[user1364702]

What are the processes?

[Michael Hampton]

And lose data. Doesn't sound like a great idea.

[Arie Skliarouk]

You lose data anyway by reboot. This way you might avoid reboot - useful feature on production or development systems.

[BT643]

Thanks, this worked for an issue we had with a script stuck attempting to access a disappeared NFS mount for weeks :)

[Marco Marsala]

This is exactly what is happening to me sometimes when I do the ls command on a s3fs mount. The ls process won't kill even with kill -9 until I force the unmount with umount -l. Alternatives to umount?

[Dustin Oprea]

@ArieSkliarouk Freaking awesome. Thanks for this little tidbit.

[Curtis Yallop]

Now my umount process is hung as a zombie STAT "D+"!

[Tim Chaubet]

This might also kill the ssh shell you're connected with.