Set resolution on headless server

Sometimes we use the headless server with a vnc desktop, the desktop will usually keep the lowest resolution (800*600). Even worse, its resolution cannot be modified directly. So we need a dummy drive to solve it.

the Following was tested in Debian 9:
first install video card drive:

apt-get install xserver-xorg-video-dummy

Then paste following in “xorg.conf”. This config file is usually not exist in modern OS. These OS can detect most of the monitor and auto setup. But we can manually setup this file to control the resolution of the headless server.

Section "Device"    Identifier  "Configured Video Device"
    Driver      "dummy"
    VideoRam 256000
EndSection


Section "Monitor"
    Identifier  "Configured Monitor"
    HorizSync 5.0 - 1000.0
    VertRefresh 5.0 - 200.0
    ModeLine "1920x1080" 148.50 1920 2448 2492 2640 1080 1084 1089 1125 +Hsync +Vsync
EndSection


Section "Screen"
    Identifier  "Default Screen"
    Monitor     "Configured Monitor"
    Device      "Configured Video Device"
    DefaultDepth 24
    SubSection "Display"
    Depth 24
    Modes "1920x1080"
    EndSubSection
EndSection

After reboot xserver or machine, you can see a VNC desktop with 1920*1080.