While for reboots one can use `reboot -f`, I was not aware of a way to do a forced shutdown, until now.
The trick is to use the Magic SysRq key:
# reboot echo 1 > /proc/sys/kernel/sysrq echo b > /proc/sysrq-trigger # shutdown echo 1 > /proc/sys/kernel/sysrq echo o > /proc/sysrq-trigger
Happy testing! :)