Re: How to go about debuging a system lockup?

[Keith Owens <kaos@ocs.com.au>]

Lennart Sorensen (on Thu, 16 Nov 2006 16:21:40 -0500) wrote:
>On Thu, Nov 16, 2006 at 09:49:06PM +0100, Jesper Juhl wrote:
>> Well, I have a few ideas that are hopefully useul.
>> 
>> - If you have not done so already, then go in to the "Kernel Hacking"
>> section of the kernel configuration and enable some (all?) of the
>> debug options and see if that produces anything that will help you
>> track down the problem.
>
>I enabled the things that sounded useful.  I will try enabling the rest.
>
>> - You could enable 'magic sysrq' and see if you can manage to get a
>> backtrace with it when it hangs (see Documentation/sysrq.txt) (ohh and
>> raise the console log level so you get all messages, including debug
>> ones).
>
>Yeah I did that.  No response to sysrq (at least not on the serial
>console.  Maybe I should get a keyboard connector put on.)  Normally we
>run without VGA/keyboard/etc, and just serial console.  Of course the
>serial console requires working interrupts.  Not sure about the keyboard
>driver.
>
>> - You could also try kdb (http://oss.sgi.com/projects/kdb/) or kgdb
>> (http://kgdb.linsyssoft.com/). That might help you pinpoint the
>> failure.
>
>Can I run that remotely somehow?  I never really looked at kdb or kgdb
>before.

kgdb can only be run remotely.  kdb can be run on the local keyboard/console
or over a serial console.