reboot hangs

[Tom H]

On Fri, Feb 11, 2011 at 4:08 AM, Jacques Beigbeder
<Jacques.Beigbeder at ens.fr> wrote:
>
> I have an Ubuntu 10.04 10 km away, it is unusable
> but I don't known how to reboot, with a SSH connection.
> I tried:
>        reboot -f
>        kill -9 -1
>        kill -15 -1
>
> df shows NFS mounts (as administrator I know),
> but also a CD and several USB devices.
>
> I tried some 'umount -f' and 'umount -l', they hang.
>
> Is there anything to do to remotely force a reboot?
> The box is 10km away, it is a small PC without IPMI.

echo r > /proc/sysrq-trigger
echo e > /proc/sysrq-trigger
echo i > /proc/sysrq-trigger
echo s > /proc/sysrq-trigger
echo u > /proc/sysrq-trigger
echo b > /proc/sysrq-trigger