Magic Sysreg key problems.

[Konstantin Svist]

On 08/20/2012 12:55 PM, Aaron Konstam wrote:
> It is hard to know where to start with the problems with the use of the
> SysReg key.. Since acording to the Wikipedia notes in order to get these
> Magic SysReg features to work you have tp add the Ctrl button. So to
> reboot you would have to use the Ctrl+Alt+SysReg+ b button. On my
> workstation Keyboard this is nearly impossible to do because of the
> position of the SysReg key in the upper right corner of the keyboard.
> On my laptop where I can hit the keys the function fails to work.
> Without the Ctrl all you get is screen shots which I do get.
>
> With the alternate approach  of:
> echo key > /proc/sysreq-trigger the reboot works but I can't detect
> anything else working.
>
> So how does one use these magic keys ?

You have to enable the sysrq key in /etc/sysctl.conf:
kernel.sysrq = 1

In non-graphical mode it's just Alt+SysRq (not Ctrl, and not Alt+Ctrl), 
but the GUI can choose to ignore the combination - there used to be some 
X keyboard setting you could set globally, but it doesn't work anymore. 
I think there's some workaround for gnome, but I never did figure out 
how to make it work right in XFCE.

Lastly, on the laptop the SysRq key might only be usable with Fn 
modifier (Ctrl+Alt+Fn+SysRq+...), though Alt+PrintScreen has worked for 
me on all laptops I've tried (in text mode)