Sudden and unexplained reboots

[Don Lewis]

On  4 Jun, Bosko Milekic wrote:
> 
> On Wed, Jun 04, 2003 at 08:13:24PM +0200, Noor Dawod wrote:
>> Hello,
>> 
>> I'm having a problem in one of the FreeBSD boxes that I manage. All of a
>> sudden, and for no particular reason, the machine just reboots abruptly.
>> When it loads up again, I cannot see an indication that there's anything
>> wrong in the configuration.
>> 
>> By the way, the machine is running like this for few months, and no
>> changes were made lately. Machine has 2GB RAM, RAID-5 disk array and a
>> Xeon 933Mhz CPU. There's enough space on disk and more free RAM to drive
>> 5 desktop computers.
>> 
>> Anyone got an idea how to debug the problem? and better, how to resolve
>> and fix it?
>> 
>> Thanks in advance.
>> 
>> /Noor
> 
>   Build a kernel with INVARIANTS and DDB options and see if you get
>   dumped to the console debugger following a trap or panic at some point.
> 
>   Also, obviously, make sure that you're not getting any power surges or
>   anything of the sort; basically anything hardware-related that could
>   possibly cause a reboot.  If you're plugged into a series-connected
>   outlet, I would advise to try a different outlet.  If you're plugged
>   into a UPS, make sure that the load on it is not too high.

I'd also check to make sure that all the fans are operational and
something isn't overheating.