Ctrl+Alt+Backspace Disabled

As stated in the Ubuntu 9.04 release notes, Ctrl-Alt-Backspace key combination to restart Xorg is disabled.

Ctrl-Alt-Backspace disabled by default in Xorg

The Ctrl-Alt-Backspace key combination to force a restart of X is now disabled by default, to eliminate the problem of accidentally triggering the key combination. Users who do want this function can enable it in their xorg.conf, or by running the command dontzap --disable.

Enable Ctrl+Alt+Backspace Again

Ubuntu Linux 9.10 Karmic Koala

* System -> Preferences -> Keyboard

Select the 'Layouts' tab -> Click the 'Layout Options' button

Click the 'Key sequence to kill the X server' to expand it -> Check the 'Control + Alt + Backspace' option -> Click the 'Close' button

Done!!!

Ubuntu Linux 9.04 Jaunty Jackalope

* Open the /etc/X11/xorg.conf file and add

Section "ServerFlags"
	Option	"DontZap"	"False"
EndSection

* Or simply use dontzap.
* If it is not installed already,

$ sudo apt-get install dontzap 

* Use the dontzap command to enable Ctrl+Alt+Backspace

$ sudo dontzap --disable 

This acually adds

Section "ServerFlags"
	Option	"DontZap"	"False"
EndSection

to the /etc/X11/xorg.conf file.

* After it is done, make sure to log out & in for the change to take effect.

* To enable the “DontZap” option again,

$ sudo dontzap --enable 

* More information about the DontZap option.

http://www.x.org/archive/X11R6.8.0/doc/xorg.conf.5.html#sect4

Option "DontZap" "boolean"

This disallows the use of the Ctrl+Alt+Backspace sequence. That sequence is normally used to terminate the Xorg server. When this option is enabled, that key sequence has no special meaning and is passed to clients. Default: off.