Re: RFC : remote driver debugging efforts

From: Jesper Juhl
Date: Sat Aug 12 2006 - 15:33:11 EST

On 12/08/06, Jesse Brandeburg <jesse.brandeburg@xxxxxxxxx> wrote:
On 8/10/06, Om N. <xhandle@xxxxxxxxx> wrote:
> (I do not have a remote power on/off switch. The driver panics so
> often that somebody has to babysit the machine to switch it off and
> on. We are in different time zones and things are not moving forward at all)

two (or three) things I've done to help this, when I'm working remotely

add panic=30 to your kernel options in grub (or echo 30 >
/proc/sys/kernel/panic) to reboot the system automatically on panic.

set grub to automatically boot the safe kernel by default, and when
making a new kernel, set grub to boot it only once with (say your
default is 0 and the new kernel is 1 in grub)

echo 'savedefault --default=1 --once' | grub --batch

set up netconsole so that you can see the kernel messages (optional) on oops.

finding out about all these was incredibly hard and obtuse :-) So
hope this helps.

If you have remote access to the keyboard/display etc, for example via
a network enabled KVM switch or similar, then magic sysrq can also be
very helpful to remotely sync & unmount filesystems, and do emergency
reboots... It can also be used to get stack dumps etc... Read
Documentation/sysrq.txt for all the details.

I'm not sure, but I think there was a patch floating around at one
point that would let you trigger sysrq remotely over the network
without even logging into the box or having remote keyboard access -
could be very useful in your case although it is ofcourse extremely

Jesper Juhl <jesper.juhl@xxxxxxxxx>
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