Today I had a machine I was working on spit the dummy in a really bad way. It had a tonne of IO errors to its root filesystem and eventually decided to remount it read only. Of course this meant that it was almost entirely wedged. I tried the reboot command, the init command and everything would lockup my terminal. Not having console or physical access to the machine I couldn’t simply hit the power button, so I used the Linux magic commands:
echo 1 > /proc/sys/kernel/sysrq echo b > /proc/sysrq-trigger
Of course the disk errors meant that it was unable to boot but ‘The Big Hammer’ struck me as something extremely useful.