Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 27 Sep 2002 22:48:13 +0300
From:      Petri Riihikallio <Petri.Riihikallio@Metis.fi>
To:        questions@FreeBSD.ORG
Subject:   Re: How to shut down cleanly by killing power
Message-ID:  <a05111b0bb9ba664541e1@[192.168.0.2]>

next in thread | raw e-mail | index | archive | help
Thanks for your reply!

>"sync" is pretty much useless, it doesn't buy you anything.
>Particularly, it won't mark your filesystems clean (so fsck
>will still have to run on the next boot), and it does not
>guarantee that there's no unwritten data left in memory.

Yes, this I found out by testing. Still many shutdown scripts include
"sync ; sync ; sync" as a mantra.

>No.  Upon shutdown, the scripts will be executed in reverse
>ASCII order.  You should rather call it something like
>"%%%whatever".  There's never a guarantee, however, that
>some clever port tries to install a "%%%%%%foo" script in
>order to get there first ...

Thanks for pointing that out!

'man rc' says just: "The scripts within each directory are executed 
in lexicographical order." I know the source IS the doc, but it is so 
slow way to find something, when you don't know what your looking for.

>So, maybe the best thing is to add your script at the end
>of /etc/rc.shutdown directly.
>  - - - -
>Yes, exactly.  This should do:
>
>umount -f -A
>mount -u -o ro /
>mount -o ro /usr

OK. Any need for 'mount -f -u -o ro /' ? (The -f forces the switch to 
ro even if files are open for writing)

Is there any reason to signal the system daemon processes (syslog, 
sshd, adjkrntz & co)?

The Linux scripts do this with killall5. It sends a signal to all 
processes except the processes in its own  session, so  it  won't 
kill the shell that is running the script it was called from.

>That's documented in /usr/src/sbin/init/init.c.

:-] "The source IS the doc"

I studied /usr/src/sys/kern/kern_shutdown.c but I couldn't find where 
the scripts were called. It is init calling the scripts and then 
calling kern_shutdown.
-- 
Cheers,
Petri

Metis / Petri Riihikallio
GSM: +358 400 505 939

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?a05111b0bb9ba664541e1>