cause of reboot

[Polytropon]

On Mon, 30 Sep 2013 20:32:39 -0400, Michael Powell wrote:
> kpneal at pobox.com wrote:
> [snip]
> > While we're throwing ideas onto the table let me mention power supplies.
> > Power supplies and hard drives are in a race to see which one will fail
> > first. It may be that the power supply is marginal and added load from
> > the drives being hit hard may send it over the edge. How heavily loaded
> > is the machine in question?
> 
> Absolute and total agreement with this.

The idea of a hardware problem looks more and more obvious here.

A software configuration problem could be located by diff'ing
the currently used files against "stock files", or by checking
the logs of a versioning system (if you use one to track your
local configuration file changes, for example in a CVS reposi-
tory).

It could be a matter of power (by "more than usual" drain when
the machine is heavily loaded), but also a file system inconsis-
tency is possible. In case the machine is using a background
fsck that silently fails to deal with a specific damage, using
background_fsck="NO" in /etc/rc.conf to _definitely_ bring the
file systems up _clean_ prior to multi-user mode booting would
probably be a good idea. Using "smartctl" to check the hard disks
SMART data would make sure the disk is not dying (and the reboot
is an effect of that).

Monitoring the server when (or while) it reboots would surely be
interesting. Maybe open some sessions to have a close look at
programs like "top", "systat -v" and "mbmon" (to check for
temperatures and voltages) - and when run at 1 second intervals,
it should be possible to obtain a good system status diagram
of the "last state" before reboot, when the connection drops.



> I once had a box where the RAM chips 
> would "sing" with a high-pitched whistle only during the 0300 periodic run. 
> It sounded just like the horizontal output on a television right before 
> destruction.  :-) 

I have heared something comparable from a graphics card when
developing some OpenGL demo stuff. :-)




-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...