UNIX for Advanced & Expert Users

Hi, I recently had an issue and by mistake a script of mine has initiated init 6 command,

Is there a way to stop the reboot manually after init 6 is given,


Your response is highly appreciated.
Thanks in advance !!

I am not aware of any means to stop a reboot. Also, you would only have a few seconds or even less before your shell is killed by the shutdown process.

I wonder if you could do "pf -ef | grep 'init 6'" then get the pid and do "kill -9 <pid>". The real question is can you do the above before you session is killed. When typing something that could cause harm, you can always pause for a moment before hitting enter and make sure that what you are doing is really what you wanted to do.

This would not work, because 'init 6' does nothing but send a signal of some sort to the real init process, the one which started when the computer booted. You'd have a fraction of a millisecond to catch 'init 6' before it sends that signal and quits.

Killing the real init process would make things worse.

That is good to know in case I do type init 6 as root on a unix system. The other problem with someone accidentally doing init 6, is that even if you can stop the shutdown from happening, the OS will start killing processes. Processes that would need to be restarted. Either way doing init 6 or shutdown on a running production server by accident is going to cause issues.

Fortunately, modern unix versions protect the init process.

Solaris 10:

Code:

# kill -9 1
kill: 1: permission denied

RHEL 6 does not even print an error message, it just discards the nonsense.

Long time ago, it was possible to kill init, which usually caused a

Code:

kernel panic: init died.

If you really want to kill init, I'd bet this would work on Solaris:

Code:

dd if=/dev/zero of=/proc/1/as

Anyone care to try?

Not sure offhand what the equivalent Linux /proc/1 entry would be.