HOWTO: Disable Ctrl-Alt-Backspace

**Amaranth** · March 18th, 2006

I'm sure everyone has hit these three buttons before. So annoying! Here is how to disable them:

Open xorg.conf for editing
Code:
```
sudo gedit /etc/X11/xorg.conf
```

Add these 3 lines to the end:

Code:

Section "Serverflags"
Option "DontZap"      "yes"
EndSection

Save the file and close gedit

Now all you have to do is run 'sudo invoke-rc.d gdm restart', hit ctrl-alt-backspace (last time it will work), or log out and ctrl-alt-backscape will be dead!

**Keymaster** · October 6th, 2008

Actually I've discovered that ServerFlags is not the right section (at least not on the 2 Ubuntu 8.04 Desktop systems I just installed)

On both my systems putting that in ServerFlags caused X to go into 640x480 and get stuck there. Not sure why, but putting it in ServerLayout worked perfectly.

Now my users can't kick each other off when they lock the screen.

BTW: If you want to prevent use switching from a locked screen I'd suggest changing the permissions on /usr/bin/gdmflexiserver to 750. User switching can still occur from unlocked sessions though.

**marcus0263** · May 9th, 2009

Originally Posted by Amaranth

I'm sure everyone has hit these three buttons before. So annoying! Here is how to disable them:

Open xorg.conf for editing
Code:
```
sudo gedit /etc/X11/xorg.conf
```

Add these 3 lines to the end:

Code:

Section "Serverflags"
Option "DontZap"      "yes"
EndSection

Save the file and close gedit

Now all you have to do is run 'sudo invoke-rc.d gdm restart', hit ctrl-alt-backspace (last time it will work), or log out and ctrl-alt-backscape will be dead!

Can you please not have this as a default setting?
users "accidently" hitting ctl-alt-backspace is laughable.

This is a "core" function in linux and essential when X locks up your system.

**Npl** · May 9th, 2009

Originally Posted by marcus0263

Can you please not have this as a default setting?
users "accidently" hitting ctl-alt-backspace is laughable.

This is a "core" function in linux and essential when X locks up your system.

essential as X locks up all the time?
why dont you just hit reset on your PC-Case if X locks up, for users this is pretty much the same as anything running on X will be killed and lost anyway if you hit Ctrl-Alt-Del.

**marcus0263** · May 9th, 2009

Originally Posted by Npl

essential as X locks up all the time?
why dont you just hit reset on your PC-Case if X locks up, for users this is pretty much the same as anything running on X will be killed and lost anyway if you hit Ctrl-Alt-Del.

Why reboot the system and do a hard reset, therefore increasing chances of file corruption when all you have to do is kill X?

Serously the lame excuse of "accidently hitting ctrl-alt-backspace" is laughable.

**Amaranth** · May 9th, 2009

This is an Xorg upstream default change, not an Ubuntu-specific change. We just agree with their decision so did not override it.

If you want Ctrl-Alt-Backspace to work you are not a regular user (they have no idea what it is anyway) so you should have no problem turning it back on.

Code:

Section "Serverflags"
Option "DontZap"      "no"
EndSection

**marcus0263** · May 9th, 2009

Originally Posted by Amaranth

This is an Xorg upstream default change, not an Ubuntu-specific change. We just agree with their decision so did not override it.

If you want Ctrl-Alt-Backspace to work you are not a regular user (they have no idea what it is anyway) so you should have no problem turning it back on.

Code:

Section "Serverflags"
Option "DontZap"      "no"
EndSection

Yeah I'll take this upstream, this is idiotic IMO. As to the "regular user", people I've converted over to Linux use this, why? If they've had X lock up on them I've told them just hit ctrl-alt-backspace and log back in. Just because a "newb" doesn't know how to use a feature doesn't mean it's useless let alone remove it.

I've read the upstream thread on this, this change was brought about because "some" Emac's users hit it by mistake. So an extremely small (and shrinking BTW) group is behind this change?

Anyway, thanks for responding

Cheers

**lwwalker** · May 21st, 2009

Originally Posted by marcus0263

Can you please not have this as a default setting?
users "accidently" hitting ctl-alt-backspace is laughable.

This is a "core" function in linux and essential when X locks up your system.

Well . . . not entirely laughable. I'm an intermediate user, and I've accidentally hit ctl-alt-backspace far more times than X has borked. My laptop's backspace key is a hair's breadth from the PageDn key. I've had a good handful of cuss-fests when aiming for ctl-alt-PageDn (change tab in gedit) and hit ctl-alt-backspace. So, accidental X11 restarts can happen.

**oomingmak** · May 23rd, 2009

Originally Posted by lwwalker

Well . . . not entirely laughable. I'm an intermediate user, and I've accidentally hit ctl-alt-backspace far more times than X has borked. My laptop's backspace key is a hair's breadth from the PageDn key. I've had a good handful of cuss-fests when aiming for ctl-alt-PageDn (change tab in gedit) and hit ctl-alt-backspace. So, accidental X11 restarts can happen.

So then surely you should disable it on your system, rather than it being forced onto the majority of users who have never had such a problem.

But as was said earlier; "what's done is done".