Yes: a watchdog timer. The kernel appears to support two or three different
watchdog cards these days.
The watchdog hardware works like a countdown timer. As long as the system
is healthy, a user process keeps resetting the countdown timer before it can
reach zero. If the system crashes or freezes, the timer reaches zero, and
the watchdog card forces a hardware reset by twiddling the reset line (or
PWROK as I recall) on the motherboard.
They're relatively cheap ISA cards, and, with the hernel support, easy to
install and use...
There's also a "software watchdog" available if you build it into the
kernel. It's less likely to successfully reboot the system in the case of
a true crash... but the price sure is right.
-Andy
Global Auctions
http://www.globalauctions.com