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From: rickert@mp.cs.niu.edu (Neil Rickert)
Newsgroups: comp.unix.misc
Subject: Re: booting a new kernel remotely
Message-ID: <1990Sep29.162137.23912@mp.cs.niu.edu>
Date: 29 Sep 90 16:21:37 GMT
References: <1990Sep29.153337.6707@ccu.umanitoba.ca>
Organization: Northern Illinois University
Lines: 23

In article <1990Sep29.153337.6707@ccu.umanitoba.ca> mills@ccu.umanitoba.ca (Gary Mills) writes:
>
>Does anyone know of a nice way to boot a new kernel when logged in via
>a dial-up line?  When I do it from the console, I do a `shutdown +5',
>and when it comes down to single-user mode, I do a couple of syncs, hit
>break to get to the monitor, and do a `b vmunix.new -s'.  When it comes
>up, I rename the kernel, and hit ^D to go to multi-user mode.  The machine
>is down for less than five minutes.  This is under SunOS 4.1.  When I'm
>dialed in, `shutdown -r +5' does not work once I have renamed
>/vmunix.new to /vmunix.  I can use `reboot', but it doesn't give the
>warning messages to the users.  Also, the boot checks all the disks, so
>the machine is down for about twenty minutes.  How do other people do this?

 You can use 'wall' to scare the users of before you rename the kernel images.
At the same time create /etc/.nologin to prevent new logins.
Next you can umount all of the disk partitions, so that on reboot only
the root partition should be checked.  Finally do the rename and reboot.

-- 
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  Neil W. Rickert, Computer Science               <rickert@cs.niu.edu>
  Northern Illinois Univ.
  DeKalb, IL 60115.                                  +1-815-753-6940