Signal: KILL

This signal causes your program to terminate. This signal cannot be caught or ignored. This is always signal #9. To terminate a process IMMEDIATELY, send it a signal 9. Note the process will not have a chance to clean up.

kill -9 is a BAD Idea

The command kill -9 (or -KILL) should only be used as a very last resort!

The KILL signal does not allow a process to run any cleanup code, which means using kill -9 may leave child processes of a parent orphaned, temporary files open, shared memory segments active, and sockets busy. This leaves the system in a messy state, and could lead to unanticipated and hard to debug problems.

Note:

• ZombieProcesses in the "Z" state cannot be killed, they are dead already and are waiting on their parents to reap them
• Processes that are blocked in the "D" state will not die until they recover from their D status.