Force gdm login screen to the primary monitor

Question

I have two monitors attached to my video card. Primary monitor has a resolution equal to 1280x1024 and the second has 1920x1200. My gdm login screen always appears on the second monitor even if it is switched off. My question is how to force gdm to show the login screen always on the primary monitor with resolution 1280x1024?

I use Nvidia GT9500 videcard in Twinview mode. I can't use Xinerama because vpdau doesn't work correclty in this mode.

What I have found is that mouse pointer always appears in the center of union of the screens and center is always on the monitor with higher resolution. Login screen always shows where mouse cursor is.

Now my primary monitor has a resolution equal to 1920x1080. The problem still persists, mouse cursor always appears in the right-bottom corner of the second monitor.

score 56 · Accepted Answer · edited May 03 '19 at 03:33

56

For newer versions of Ubuntu such as 13.10 or upgraded 13.04 using Gnome 3.8, this procedure is different because the X configuration file no longer controls the monitor layout. You must do the following:

Set the monitor layout correctly as a logged-in user (see Permanantly set monitor as primary)
Copy the configuration file over to the gdm settings
```
cp ~/.config/monitors.xml ~gdm/.config/
```

For more details, see https://bbs.archlinux.org/viewtopic.php?id=161903

Within the monitors.xml file there are tags labeled: <primary>something</primary>

For the monitor you want to be primary put a 'yes' in between the tags and a 'no' for all other screens. ex: <primary>yes</primary>

edited May 03 '19 at 03:33

Community

1

answered Sep 18 '13 at 18:40

Andrew Mao

1,721
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Confirmed, it works for GNOME 3.10 as well. The absolute location of ~gdm/.config/ is /var/lib/gdm/.config/ in case anyone else wonders. – Forage Nov 28 '13 at 19:13
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seen on gnome 3.14: sudo cp ~/.config/monitors.xml /var/lib/gdm3/.config/ – Francois Nov 20 '16 at 10:35
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I can confirm that this simple trick works on Ubuntu 17.04 with Gnome 3.24.2 as well. I just ran the command @Francois posted and now it works like a charm. – fgblomqvist Jul 11 '17 at 13:19
2

Still works in 17.10 using Xorg. But don't try to get smart and symlink your user configuration. It will not work. – raphinesse Nov 04 '17 at 12:10
This should be marked as the correct answer. – AzP Oct 01 '18 at 19:00
Worked also for Pop_OS! 18.10 – msmafra Feb 02 '19 at 22:44
This worked on Ubuntu 20.04 with Gnome 3.36.9. I had to do sudo for cp as ~/ggm/.config is owned by gdm user - not currently logged in user. I also had to reboot the machine for the config change to take effect (log off doesn't restart gdm) – Soichi Hayashi Jun 16 '21 at 13:47
This answer, using the @Francois command, works on Ubuntu 21.10. It also provides gdm greeter with the correct monitor layout (which monitor is on the left and which is on the right etc). – Tim Richardson Nov 14 '21 at 11:15
I found it useful to rename ~/.config/monitors.xml before running the display settings app, because the existing monitors.xml had a lot of cruft from previous monitor setups. The display settings app will then create a new, "clean" file and it is easier to see what is going on (setting primary, secondary monitor x/y location, etc). – Troy Folger Sep 22 '22 at 20:00
If ~gdm (/var/lib/gdm3) does not exist, use sudo mkdir -p ~gdm/.config/; sudo chown -R gdm:gdm ~gdm; sudo cp ~/.config/monitors.xml ~gdm/.config/ – Gibezynu Nu Jun 06 '23 at 15:01

score 3 · Answer 2 · answered Nov 07 '10 at 07:47

3

are you using a Nvidia card with a dual-screen setup?

If so, I had the same problem, and solved it the following way: Switch off the computer, unplug the second monitor, switch the computer back on, run 'sudo nvidia-settings', plug the second monitor back in, run 'Detect Displays' in the Nvidia GUI, and make the necessary configurations before saving the settings. The IMPORTANT point is that the screen that you wish the login to show up in is set to 'Screen Number: 0'.

In my case, leaving the second monitor plugged in before running 'nvidia-settings' left it as screen 0 for some reason, but by plugging it in after, this was sorted.

answered Nov 07 '10 at 07:47

Yes, I use Nvidia card in TwinView mode. In this mode every screen is screen 0. So unplugging didn't help. – Kirill V. Lyadvinsky Nov 07 '10 at 09:36
Okay, no experience with TwinView so sorry can't be of any more assistance – Nov 09 '10 at 20:30
I had to start nvidia-settings, X Server Display Configuration -> Save to X Configuration File -> Show preview -> copy paste all the content to /etc/X11/xorg.conf.d/nvidia.conf – morhook Oct 03 '23 at 20:40

score 2 · Answer 3 · answered Jun 27 '23 at 01:05

2

Old solutions do not work because the name of the gdm folder has changed. Here is the command to fix the issue of gdm displaying on the correct screen.

sudo cp ~/.config/monitors.xml /var/lib/gdm3/.config/monitors.xml

answered Jun 27 '23 at 01:05

uvea

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Worked for me on Debian 12. Thanks! – scrutari Sep 03 '23 at 16:28

score 1 · Answer 4 · edited Jan 25 '23 at 15:46

I am using Ubuntu 22.04 and for me this link works.

Only the path for copying destination changed over the last years a little bit from /var/lib/gdm/.config/ to /var/lib/gdm3/.config/.

Change settings to single-mode in Settings → Displays.
Copy the monitors.xml file from ~/.config/monitors.xml to /var/lib/gdm3/.config/.
Restart your PC.
Change the setting back to dual screen in Settings → Displays.
Copying again the monitors.xml file from ~/.config/monitors.xml to /var/lib/gdm3/.config/ (otherwise the second monitor turns on/off on boot).

That's it.

score 1 · Answer 5 · answered Jan 12 '11 at 10:57

1

If twinview does it the same way the ATI catalyst control center does it, there is a xorg.conf you can edit with gksu gedit /etc/X11/xorg.conf

The relevant part of mine looks like this:

Section "ServerLayout"
    Identifier     "amdcccle Layout"
    Screen      0  "amdcccle-Screen[1]-0" 0 0
    Screen         "amdcccle-Screen[1]-1" 1400 0
EndSection

All you have to do (after backing up your xorg.conf of course) is change the ServerLayout by swapping the Screen entries (and adapting the screen numbers), in my case that would be:

Section "ServerLayout"
    Identifier     "amdcccle Layout"
    Screen      0  "amdcccle-Screen[1]-1" 1400 0
    Screen         "amdcccle-Screen[1]-0" 0 0
EndSection

answered Jan 12 '11 at 10:57

Tobias Kienzler

446

I have only one screen defined in the xorg.conf so this doesn't help. – Kirill V. Lyadvinsky Jan 12 '11 at 20:48
@Kirill: can you swap the plugs and then change screen ordering in the nvidia settings? – Tobias Kienzler Jan 13 '11 at 08:57
It didn't help. Mouse always appears in the center of union of the screens and center is always on the monitor with higher resolution. Login screen always shows where mouse cursor is. – Kirill V. Lyadvinsky Jan 13 '11 at 12:08

score 1 · Answer 6 · answered Nov 30 '11 at 11:08

1

You can try "Separate X screen setting" on the NVIDIA X Server settings. If you set the desired display to 0, the login window will appear there. It's working for me.

answered Nov 30 '11 at 11:08

kissgyorgy

132

I've tried this, but Gnome3 crashes each time on login in this mode. – Kirill V. Lyadvinsky Dec 02 '11 at 19:48

score 0 · Answer 7 · answered Nov 06 '10 at 13:59

0

try switching the left/right order of your monitors, it doesn't change which one is primary, but it might help making your GDM show up.

answered Nov 06 '10 at 13:59

hansioux

1,035

it didn't help. – Kirill V. Lyadvinsky Nov 06 '10 at 17:20

Force gdm login screen to the primary monitor

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