Magic SysRq key on Lenovo Ideapad U300s ultrabook

Ubuntu has a thing called the “Magic SysRq key“, provided by the Linux kernel, which allows you to restart your machine in a safe way if it gets seriously wedged. Useful when you need it. However, I’ve got a Lenovo U300s laptop, and it doesn’t have a SysRq key.

It does still work, though. To do a “magic sysrq thing”, you press SysRq and then a letter, or combination of letters: the reboot command is the letters REISUB (which is “busier” backwards). To do that on the U300s, the “SysRq key” is ctrl-alt-fn-prtsc. What this means is, to reboot, do this:

  • Press and hold Ctrl
  • Press and hold Alt
  • Press and hold Fn
  • Press and hold PrtSc
  • Release Fn
  • Keeping Ctrl, Alt, and PrtSc held down, press and release R
  • Still keeping Ctrl, Alt, and PrtSc held down, press and release the other “REISUB” keys in order, leaving a couple of seconds between each one: E I S U B
  • Your machine should reboot.