How do I select which monitor kdm will display login on?

[Ian Chapman]

On 13/03/14 20:22, Tim wrote:
> Allegedly, on or about 13 March 2014, Ian Chapman sent:
>> I was having similar issues with GDM, where it would set up the order
>> of the monitors incorrectly, despite what was in the X configuration
>> or the desktop settings. Interestingly enough, the order was correct
>> when I logged in.
>
> *Your* settings are loaded when you log in, they're specific to you, and
> stored in your ~/.config/monitors.xml
>
> GDM runs as the gdm user, and it can have its monitor configuration
> settings set in /var/lib/gdm/.config/monitors.xml (gdm's home space
> is /var/lib/gdm).

Yes, I realise that the user can have different settings to the display 
manager. However, here's the interesting thing. From a VT if I login and do:

init 3
systemctl disable lightdm.service
systemctl enable gdm.service
init 5

GDM starts, but the logical order of the monitors is wrong. The login 
dialog opens on the right monitor, but I have to move the mouse off the 
right edge to go to the left monitor.

Then without changing any X config

init 3
systemctl enable lightdm.service
systemctl disable gdm.service
init 5

LightDM starts, and the logical order of the monitors is correct. I move 
the mouse off the left edge to move to the left monitor.

If I delete my personal monitors.xml file, then when I login I inherit 
whatever order GDM or LightDM uses.

So at the very least, it tells me that GDM and LightDM do not use the 
same mechanism for deciding the ordering of monitors.

-- 
Ian Chapman.