I am trying to kill a du -mh command that has been stuck running for 18 hours. I have tried many kill signals kill -15, kill -2, kill -9 as root but with no luck. Are there any other techniques to kill this process?

Note this is in R running state, yet it does not appear to be responding to my kill signals.

Screenshot of top command

 ps -Z 31806
 LABEL                             PID TTY      STAT   TIME COMMAND
 unconfined                      31806 ?        RN   1137:41 du
  • You can't kill a zombie, it's already dead. I have no idea what those many SE answers are talking about. You're probably rather thinking of processes stuck in an uninterruptible sleep (D, not R state). In your case: maybe you don't have permission to kill it? Try strace -e trace=kill kill PID, and if that shows that the kill() is successful, attach to the df process with strace -p PID, kill it and see how it's reacting to the signal.
    – mosvy
    Aug 6, 2019 at 11:11
  • @mosvy strace -e trace=kill kill PID returns exit code 0, and strace -p PID shows attached, but no output following kill, kill -9 command Aug 6, 2019 at 11:18
  • @mosvy you're right, I've removed the mention of zombie state from my question. Aug 6, 2019 at 11:26
  • 1
    Which means that it cannot attach it (strace succeeds because it uses PTRACE_SEIZE which doesn't stop the process). This may be some kind of kernel bug -- also see this old question.
    – mosvy
    Aug 6, 2019 at 12:58
  • 1
    do/did you have any NFS mounts on that VM? If so, see nfs(5) and read the info on the soft and hard mount options (which control timeout & retry behaviour, effectively giving you a choice between hangs like this or the risk of data corruption). I ask because I've seen hangs on df or du many times over the years when an NFS server doesn't respond to an NFS client.
    – cas
    Aug 6, 2019 at 23:38

1 Answer 1


You could use :

kill -kill PID

This is very common command for force kill PID.

  • 1
    short / friendly name for kill -9 PID which I have already tried Aug 6, 2019 at 16:04

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