howto debug a complete hard reset

[Jeremie Le Hen]

Hi Alexander,

On Fri, Apr 13, 2012 at 09:36:44PM +0000, Alexander Best wrote:
> 
> i'm running HEAD on amd64 and experienced some really annoying resets during
> the last couple of months.
> 
> when i do 'sysctl -a' or 'sysctl -a|grep bla', my whole system does a hard
> reset. no core dump gets produced.
> 
> isn't there a way to find out which sysctl variable is causing the reset?

This is probably a sysctl handler that is causing the reboot.  You can
run this one-liner to spot the culprit (use sh):

    for i in $(sysctl -Na); do sysctl $i >> ~/sysctl.out; sync; done

Each sysctl will be called in turn and the output is appended to a file,
but the file will forcibly written to the disk before the next
occurence.

When your computer will be reset, the culprit will obviously not be
written to this file, but the previous one will.  You can then look at
the output of sysctl -Na to see which one is causing the reboot.

Regards,
-- 
Jeremie Le Hen

Men are born free and equal.  Later on, they're on their own.
				Jean Yanne