Somewhere along the line, the Ubuntu development team disabled a standardized keyboard shortcut that many long-time Linux users had grown accustomed to. Namely: using the ctrl-alt-backspace key combo for quickly and conveniently restarting the system’s X window system when needed.



As a Linux user for over a decade, I hesitate to admit that my system ever crashes. But let’s be straight about it: like all software, Linux apps can occasionally crash and freeze up the desktop. When this happens, it’s handy to be able to hit ctrl-alt-backspace and restart the desktop without having to resort to pressing the system’s reset button. It’s very rare — but frankly, it does happen once in a while.

Although it’s easy to activate Ubuntu’s optional ctrl-alt-backspace key combo for restarting the X window system, the required configuration setting is somewhat obscure. Additionally, I recently googled the issue and found several blog and forum posts that provide instructions that don’t reflect the current version of Ubuntu. So, the purpose of this short post is to document the procedure as of Ubuntu 10.10.

Enabling Ubuntu’s ctrl-alt-backspace X server reset function

Follow these simple steps:

Go to Menu > System > Preferences > Keyboard

Select the Layouts tab

Click the Options button

Click the Triangle to the left of the line that says “Key sequence to kill the X server”

Check the box to the left of Ctrl + Alt + Backspace

That’s it. The screenshots below show a few aspects of the process.











Why would you want to use this command? Basically, it’s a way to reset a portion of your system — the X window system — in case it ever freezes up, without resorting to pushing the reset button. Bear in mind, however, that any apps running on top of X will be stopped ungracefully, resulting in possible loss of data.

Naturally, if an application crashes in a manner that disables the keyboard driver, pressing ctrl-alt-backspace won’t do anything. In that case, you might try unplugging the keyboard and plugging it back in again, in hopes that it will get recognized and reactivated by the system. Or, if your system happens to have an ssh server running on it, you could log in remotely and shut the system down gracefully.

