Safely recover from a freeze in Ubuntu

If you ever encounter a system lockup in Ubuntu here’s a little trick you can use to safely restart your computer.

Hold down the Alt and PrtScn/SysRq keys at the same time and, keeping them held down, enter the following sequence of keys: R, E, I, S, U, B. Hold each key down for a second or so and don’t rush.

What it does is it allow Linux to take control of your system, requests politely that all processes close, forces all processes to close, flushes data to disk, unmounts your filesystems and reboots.

Here’s a couple of mnemonics: ”Raising Elephants ISUtterly Boring” or “Reboot Even ISystem Utterly Broken”.

It’s extremely rare that this is necessary due to Linux’s stability but I’ve found I’ve needed this a couple of times recently (I suspect Google Chrome is the culprit) so I’m posting this here for easy future reference from my phone.

Tags: , ,

One Response to “Safely recover from a freeze in Ubuntu”

  1. Thanks for posting this! I’ve been running Linux in a production environment for over 10 years, and much longer than that if you start counting from when I first started flirting with Slack way back when… and I never had any idea that you could send sync signals to a locked up system. Linux is stable – really stable. I’ve only had a few lock ups in all the years I’ve been running Linux. I have corrupted the file system twice by forcing a power off. But that’s twice too many, now that I know the trick. Thanks again!

Leave a Reply