title: Problem adding extra loginctl seat for a Multiseat headless xserver-xorg-video-dummy driver on Ubuntu bionic 18.04?
body: <p>I am trying to add an extra headless seat/session to allow LightDM to offer a headless login page for VNC users without interfering with the person using the desktop.  I tried several configurations (with no discernible errors in the logs) similar to the following tutorials for an nVidia card and another adapter:</p>
  
  <p><a href="https://techoverflow.net/2019/02/23/how-to-run-x-server-using-xserver-xorg-video-dummy-driver-on-ubuntu/" rel="nofollow noreferrer">https://techoverflow.net/2019/02/23/how-to-run-x-server-using-xserver-xorg-video-dummy-driver-on-ubuntu/</a></p>
  
  <p><a href="https://wiki.archlinux.org/index.php/Xorg_multiseat" rel="nofollow noreferrer">https://wiki.archlinux.org/index.php/Xorg_multiseat</a></p>
  
  <p><a href="https://wiki.ubuntu.com/MultiseatTeam/Instructions" rel="nofollow noreferrer">https://wiki.ubuntu.com/MultiseatTeam/Instructions</a></p>
  
  <p>However, so far the newer <strong>systemd</strong> related Xorg configuration process ignores the Xorg "<strong>dummy</strong>" driver in the examples (for a detached VNC desktop under a separate user login). Notably, the lightDM  settings are loaded for the detected nVidia [Seat:card0] setup, but as the [Seat:seat4] is never polled by <strong>loginctl</strong> it's conf is never applied in LightDM.</p>
  
  <pre><code>$ls -l /tmp/.X11-unix/
  srwxrwxrwx 1 root root 0 Jun 16 23:09 X0
  
  $loginctl list-seats
  SEAT            
  seat0           
  1 seats listed.
  
  $loginctl
     SESSION        UID USER             SEAT             TTY             
           2       1000 pi                                                
          c1        118 lightdm          seat0  
  
  $ps aux | grep X
  root      6732  5.1  0.2 263360 48232 ?        Sl   23:09   0:01 /usr/lib/xorg/Xorg -s 0 -dpms -keeptty :0 -config /etc/X11/xorg.conf -layout Layout0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
  
  $ls -l /sys/class/graphics
  lrwxrwxrwx 1 root root 0 Jun 16 23:09 fb0 -&gt; ../../devices/platform/vesa-framebuffer.0/graphics/fb0
  lrwxrwxrwx 1 root root 0 Jun 16 23:09 fbcon -&gt; ../../devices/virtual/graphics/fbcon
  </code></pre>
  
  <p>Manual setup:</p>
  
  <pre><code>$sudo nvidia-xconfig
  $sudo nano  /usr/share/X11/xorg.conf.d/10-Dummy.conf
  Section "Device"
    Identifier "Card4"
      Driver      "dummy"
    VideoRam 32768
    Option "NoDDC" "true"
    Option "IgnoreEDID" "true"
  EndSection
  
  Section "Monitor"
    Identifier "Monitor4"
    Modeline "1920x1080_60.00" 172.80 1920 2040 2248 2576 1080 1081 1084 1118 -hsync +vsync
    Modeline "1280x1024_60.00"  109.00  1280 1368 1496 1712  1024 1027 1034 1063 -hsync +vsync
    Modeline "1024x768_60.00"   63.50  1024 1072 1176 1328  768 771 775 798 -hsync +vsync
    Option      "Primary" "true"
  EndSection
  
  Section "Screen"
    Identifier "Screen4"
    Device "Card4"
    Monitor "Monitor4"
      DefaultDepth 24
      SubSection "Display"
      Depth 24
      Modes "1920x1080_60.00"  "1280x1024_60.00" "1024x768_60.00"
      EndSubSection
  EndSection
  
  $sudo nano  /usr/share/X11/xorg.conf.d/10-Dummy-seat4.conf
  Section "ServerLayout"
  Identifier     "Dummy4"
  Screen       4 "Screen4"
  Option   "Seat" "seat4"
  Option   "Xinerama" "0"
  Option          "SingleCard" "on"
  EndSection
  </code></pre>