Freebsd - restarting itself?!

Jason Hunt leth at
Thu Mar 27 15:39:26 PST 2003

On Mon, Mar 24, 2003 at 11:20:56AM -0800, Steve Warwick wrote:
> Hi All, 
> Is it possible for FreeBSD to shut itself down and restart for no reason?
> My machine was restarted last night and my hosting company claims they did
> not touch the server or have any problems. This has been going of for a few
> months now -- intermittent restarts that no one claims responsibility for.
> This is a new machine with the latest OS (4.7) so I can't blame a faulty
> power supply or something like -- I have more fans than Britney in the
> server, for HD and CPU so I don't think it's a temp problem.

Run /usr/bin/last and check the line below the last 'reboot' (which is
when the system came up).

If you see 'shutdown', then FreeBSD did a clean shutdown because someone
or something told it to do so.  Any users that are logged in to the
system will have 'shutdown' as their logout time.

If there is no 'shutdown' before the reboot, then the system did not
cleanly restart.  You would also likely see "/ not cleanly unmounted,
checking" (that is not the exact message, but it is similar) in dmesg
before the "Mounting root from ..." line.  If any users were logged in,
you will see 'crash' as their logout time.  Here are two examples;

This is "normal".  I shut down the system myself:

reboot           ~                         Thu Mar 27 17:40
shutdown         ~                         Thu Mar 27 17:39
root             ttyv0                     Thu Mar 27 17:27 - shutdown (00:12)

This is a "crash".  The power flickered in this case:

reboot           ~                         Mon Feb 24 00:52
jhunt            ttyv0                     Sun Feb 23 12:31 - crash (12:20)

If there was not a clean shutdown, I would start looking for faulty
hardware, assuming the power was not interrupted.  Any machine that
spontaniously reboots on its' own usually has a bad power supply, but it
could be very well be the motherboard, or even something else.  Further,
as many other people have said, just because the hardware is new does not
necessarily mean it is problem-free.

Hope this helps.

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