1️⃣ Version Info
- Ubuntu 24/22/20/18
- Todesk/AnyView
- xserver-xorg-video-dummy
2️⃣ Install & Configure a Virtual Display
- Install the dummy video driver:
sudo apt install xserver-xorg-video-dummy
- Edit
/etc/gdm3/custom.conf
to disable Wayland and force X11 (so that Todesk, etc., which may not support Wayland, can work):WaylandEnable=false
- Under the directory
/usr/share/X11/xorg.conf.d/
, create a new display configuration file named99-dummy.conf
# 99-dummy.conf
Section "Device"
Identifier "Configured Video Device"
Driver "dummy"
VideoRam 256000
EndSection
Section "Monitor"
Identifier "Configured Monitor"
HorizSync 10.0-300
VertRefresh 10.0-200
EndSection
Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
DefaultDepth 24
SubSection "Display"
Depth 24
Modes "1920x1080"
EndSubSection
EndSection
3️⃣ After Reboot, Verify
Run:
xrandr
You should see a display output such as “1920×1080 (dummy)” or similar.
Explanation & Notes
- By installing and configuring the dummy video driver, even when there is no physical monitor connected, the system still behaves as if a display is present. This avoids remote desktop black screen issues when using tools like Todesk.
- Since Todesk does not support Wayland in Ubuntu, you must ensure the system uses an X11 session (disable Wayland).
- After reboot,
xrandr
it should show the dummy monitor. - If you later plug in an actual monitor and don’t want to use the virtual dummy display, you can remove or disable the configuration and reboot.
- This approach is widely used to solve the issue where disconnecting a physical display (or running a headless server) leads to no graphical output or remote control black screen.