Subject: Re: The new rc.d stuff...
To: Secret Asian Man <blymn@baea.com.au (Brett Lymn), cchen@nougat.org>
From: John Nemeth <jnemeth@victoria.tc.ca>
List: current-users
Date: 04/23/2000 13:13:03
On Jul 23,  8:27am, Brett Lymn wrote:
} According to Secret Asian Man:
} >
} >What kind of argument is this? If your system screws up, there's always
} >single user mode. 
} 
} I think the point more was that if you screw up the script then that
} particular service is hosed not the rest from then on in.  If you have

     In my experience, any startup problem will prevent the system from
going multi-user.  I'm not saying that's the way it has to be, just
that's the way it seems to be.

} >Frankly, I'm tired of all these systems of initalization
} >that think modularity and abstraction are ways of achieving godliness,
} >because they aren't. Sure, isn't it fun to start and stop processes using
} >cute little scripts?
} 
} Fun, no not fun but just imagine your /var/spool/mqueue has just been
} filled with an absolutely huge mail file someone is trying to send
} out.  Is it easier to tell someone to:
} 
} a) run /etc/init.d/sendmail stop and then rm the big file in
}   /var/spool/mqueue, run /etc/init.d/sendmail start.
} 
} b) type "kill -KILL `cat /var/run/sendmail.pid`", rm the file and then
}    type /usr/sbin/sendmail -bd -q1h

c) just rm the file (and the corresponding qf file); sendmail won't care,
   at worst, you'll get a message in your syslog

} Try talking someone through both on a mobile phone next to a busy road
} and see which is more likely to succeed.  You get extra points if the
} person knows the difference between a back-tick and a single quote.

     When I was still doing PC support for machines running MS-DOS, I
often had to tell people the difference between a semi-colon and a
colon.  I felt like asking them if they had passed Grade 5 (it's
amazing the number of people that don't know basic punctuation).

Me:  Type "a:".
Them:  It says "bad command or filename".
Me (thinking what an idiot):  You have to press the shift key...

} > But don't we have pid files?
} 
} Which don't mean a thing when you type shutdown, you end up crafting
} your own shutdown scripts to shut things down properly before the
} system goes down.  Do you think an Oracle database takes kindly to
} getting hit with a HUP signal and then being clobbered by a KILL a
} little while later?  If that is too high faluting for you, what about

     Actually, it would be TERM followed by KILL, and if it doesn't
take kindly, then it is broken!  In fact, there is no guarantee of a
chance to do a clean shutdown due to things like (sudden power failure,
hardware failure, kernel panic, idiotic kernel which oversubscribes
swap killing processes at random, sysadmin doing 'kill -9' on wrong
process, etc.).  In otherwords, it better be prepared to go down
without notice and have some way of coming up cleanly.  Anything less
is a major design flaw.  There is no excuse for not shutting down
properly upon receipt of TERM.

} set up the rc scripts properly you can ensure all your services shut
} down in a controlled manner, this is something that has been lacking
} in the BSD world for a long time.

     See last sentence of above paragraph.

} >Forward? To what? To runlevels? You're scaring me.
} 
} Feh - you have two at the moment, Single user and multi-user.

     And, that is enough.

}-- End of excerpt from Brett Lymn