IBM Support

Removing a Defunct process

Troubleshooting


Problem

The Unix command ps lists a process as and it cannot be killed. What is a defunct process and how to remove it?

Symptom


An operating system process has exited but the ps command output still includes the process id (PID) and lists "<defunct>" in the command name column.


Example:

This is output from the ps command run on Unixware that shows that process number 1537 is defunct:

$  ps -p1537
  PID  CLS PRI TTY      TIME COMD
 1537                   0:00 <defunct>

A process in this state is called a defunct process. A defunct process is also called a zombie process, or an orphaned process.

In some cases certain resources such as memory may continue to be associated with a defunct process and will not be available for use.

A defunct process cannot be killed.

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Document Information

Modified date:
03 June 2021

UID

swg21106945

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