Freeze Recovery
From: "David A. Bandel" <david@pananix.com>
Next time something like this happens (hard freeze), try this
key sequence:
<Alt><SysRq>u (twice)
<Alt><SysRq>s (3 x)
<Alt><SysRq>b
Your system should reboot and come up without needing an
fsck.
Marcus Meissner <marcus@jet.franken.de>
You however need to do:
echo -n 1 > /proc/sys/kernel/sysrq
somewhere in your bootup scripts, since it is (runtime)
disabled by default.