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A process in an uninterruptable sleep state is waiting for device input/output, and cannot handle signals, until the process returns from the system call or trap.


Process does not respond to kill -9

Attempting to kill a process that has frozen in an uninterruptable sleep state will not work:

kill -9 foobar # This will not work for processes in uninterruptable sleep state

The kill signal will only be noticed when the process returns from the system call or trap. A process continually sleeping uninterruptable sleep state is almost always certainly inside a either a device driver with bad hardware, or containing buggy driver code.

Try killing the parent process

It is possible, though not likely that the process has hung inside another system call, not necessarily a device driver call. If this is the case, killing the parent, may resuscitate the hung process, for it to receive its kill signal:

kill -9 parent

If the init process becomes the new process

If killing the parent does not work, the hung process stays frozen, but its parent process becomes the init process (number 1).

Reboot if all else fails

At this point, it may be necessary to reboot the computer in order to remove the frozen process.

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Last modified: Fri, 05 Sep 2008 23:25:00 +0000 Hits: 1,880