Though it’s very rare, still there are instances when your Linux box becomes unstable/unresponsive and
<Ctrl-Alt-Bksp> etc. doesn’t work. Try to switch to tty1 (press
<Ctrl-Alt-F1>) and issue a reboot. If that fails as well, then your savior is reisub. Use it as explained below:
Alt-SysRq-r //switch keyboard to raw mode Alt-SysRq-s //sync disk Alt-SysRq-e //terminate all processes Alt-SysRq-i //kill all processes Alt-SysRq-u //remount all filesystems in read-only mode Alt-SysRq-b //reboot
SysRq is almost always the same as the PrintScreen button. Please wait a few seconds between key presses.
In case it doesn’t work, your sysrq is disabled. Run the following and try again:
# echo 1 > /proc/sys/kernel/sysrq