Path: utzoo!attcan!uunet!nih-csl!lhc!adm!news
From: rbottin@atl.calstate.edu
Newsgroups: comp.unix.questions
Subject: Re: Kill -9
Message-ID: <24868@adm.BRL.MIL>
Date: 26 Oct 90 23:55:46 GMT
Sender: news@adm.BRL.MIL
Lines: 46


This message is a reply from rbottin

===============================================

No there is no more powerful kill than -9. There is no real
hierarchy implied by the numbering - just different reasons
for sending a message to a process. Its just that it is
either impossible or very bad practice for a program to catch the -9
signal and ignore it....

On some UNIXes any hardware interupt hard a higher priority than the
signals that the software could send, and so once a process hangs up waiting
for a tape drive then ONLY an interupt from the TAPE wakes it up.
(your milage may vary)
In one case the processor in the tape drive was waiting for a signal
from the CPU and ignoring most of its buttons, while the
UNIX was wouldn't talk to the tape untilt the hung process was
not using the tape drive - deadly embrace.....
The only thing to do was to shutdown, ignore the complaints about
hung processes (or don't panic about them)....and reboot with tape
turned on...
dick botting (rbotting@atl.calstate.edu, dick@realsoonnow.csubnet.edu,...)
 


This is the original messsage
===============================================

Subject:  kill -9

Is there a stronger kill than kill -9?  I had a process which attached
itself to my tape drive and then locked up.  I couldn't kill it no
matter what I tried.  This caused me great concern, backups are very
important to me and I couldn't access the tape drive with this process
on it.  I shut down the system (two of my file systems didn't unmount
because of the process and shutting down didn't kill the process either) 
and rebooted.

Any suggestions.

Norm Frech < frech@mwraaa.army.mil >

 
This is a carbon copy of a message
sent by rbottin.