Trivial questions about CNTL-ALT-DEL and CNTL-ALT-BACKSPACE

Tim Judd tajudd at
Mon Nov 9 22:43:23 UTC 2009

On 11/9/09, Ronald F. Guilmette <rfg at> wrote:
> I've just been installing 7.2-RELEASE/amd64 on a fresh/wiped system
> that I plan to use as my future "main" workstation.
> Anyway, I've already noticed a couple of things that seem to be different
> from prior release that I need to ask about, i.e.:
> 1)  It appears that CNTL-ALT-DEL now causes a shutdown/reboot.  (I don't
> know what release this new feature started in... I only just noticed it
> now.)  Anyway, I'd like to know how I can disable this particular bit of
> functionality. How do I do that?

# sysctl -d hw.syscons.kbd_reboot
hw.syscons.kbd_reboot: enable keyboard reboot

> 2)  Prior versions of X (Xorg?) allowed CNTL-ALT-BACKSPACE to cause an
> immediate shutdown of the X server, but now, that doesn't see to work
> anymore.  How can I (re-)enable this functionality?

Thanks to the new versions of xorg, they removed that functionality.
A config file with "DontZap" equal to "off" re-enables it.

Google for DontZap to find where to put it in the config.

> Thanks in advance for any answers.

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