Implementation of Ubuntu20.04 VNC Installation and Setup

VNC is a remote desktop protocol. Remote control of Ubuntu 20.04 with VNC can be achieved by following the instructions in this article. The VNC installation mode like 1 cannot be used when the host is not plugged into the monitor. The following operations can work normally when the host has and does not have a monitor.

Install x11vnc first

sudo apt-get install x11vnc -y

Set the vnc password

sudo x11vnc -storepasswd /etc/x11vnc.pass 

Create an x11vnc self-starting service

Creat/etc/systemd/system/x11vnc. service and write the following

[Unit]
Description=Start x11vnc at startup.
After=multi-user.target
[Service]
Type=simple
ExecStart=/usr/bin/x11vnc -auth /run/user/1000/gdm/Xauthority -forever -loop -noxdamage -repeat -rfbauth /etc/x11vnc.pass -rfbport 5900 -shared
[Install]
WantedBy=multi-user.target

Start the x11vnc service

sudo systemctl enable x11vnc
sudo service x11vnc start

At this time, if the monitor is connected to the remote host, it can be accessed through VNC in the LAN.

In order to ensure that the remote host can be accessed remotely through VNC regardless of whether it has a monitor or not, we also need to make the following modifications

Create the default xorg. conf file

sudo Xorg :1 -configure

The program generates the/root/xorg. conf. new file

My default file content is as follows

Section "ServerLayout"
 Identifier   "X.org Configured"
 Screen   0 "Screen0" 0 0
 InputDevice  "Mouse0" "CorePointer"
 InputDevice  "Keyboard0" "CoreKeyboard"
EndSection

Section "Files"
 ModulePath  "/usr/lib/xorg/modules"
 FontPath   "/usr/share/fonts/X11/misc"
 FontPath   "/usr/share/fonts/X11/cyrillic"
 FontPath   "/usr/share/fonts/X11/100dpi/:unscaled"
 FontPath   "/usr/share/fonts/X11/75dpi/:unscaled"
 FontPath   "/usr/share/fonts/X11/Type1"
 FontPath   "/usr/share/fonts/X11/100dpi"
 FontPath   "/usr/share/fonts/X11/75dpi"
 FontPath   "built-ins"
EndSection

Section "Module"
 Load "glx"
EndSection

Section "InputDevice"
 Identifier "Keyboard0"
 Driver   "kbd"
EndSection

Section "InputDevice"
 Identifier "Mouse0"
 Driver   "mouse"
 Option   "Protocol" "auto"
 Option   "Device" "/dev/input/mice"
 Option   "ZAxisMapping" "4 5 6 7"
EndSection

Section "Monitor"
 Identifier  "Monitor0"
 VendorName  "Monitor Vendor"
 ModelName  "Monitor Model"
EndSection

Section "Device"
    ### Available Driver options are:-
    ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
    ### <string>: "String", <freq>: "<f> Hz/kHz/MHz",
    ### <percent>: "<f>%"
    ### [arg]: arg optional
    #Option   "Accel"        # [<bool>]
    #Option   "AccelMethod"     # <str>
    #Option   "Backlight"      # <str>
    #Option   "CustomEDID"     # <str>
    #Option   "DRI"         # <str>
    #Option   "Present"       # [<bool>]
    #Option   "ColorKey"      # <i>
    #Option   "VideoKey"      # <i>
    #Option   "Tiling"       # [<bool>]
    #Option   "LinearFramebuffer"  # [<bool>]
    #Option   "HWRotation"     # [<bool>]
    #Option   "VSync"        # [<bool>]
    #Option   "PageFlip"      # [<bool>]
    #Option   "SwapbuffersWait"   # [<bool>]
    #Option   "TripleBuffer"    # [<bool>]
    #Option   "XvPreferOverlay"   # [<bool>]
    #Option   "HotPlug"       # [<bool>]
    #Option   "ReprobeOutputs"   # [<bool>]
    #Option   "XvMC"        # [<bool>]
    #Option   "ZaphodHeads"     # <str>
    #Option   "VirtualHeads"    # <i>
    #Option   "TearFree"      # [<bool>]
    #Option   "PerCrtcPixmaps"   # [<bool>]
    #Option   "FallbackDebug"    # [<bool>]
    #Option   "DebugFlushBatches"  # [<bool>]
    #Option   "DebugFlushCaches"  # [<bool>]
    #Option   "DebugWait"      # [<bool>]
    #Option   "BufferCache"     # [<bool>]
 Identifier "Card0"
 Driver   "intel"
 BusID    "PCI:0:2:0"
EndSection

Section "Screen"
 Identifier "Screen0"
 Device   "Card0"
 Monitor  "Monitor0"
 SubSection "Display"
 Viewport  0 0
 Depth   1
 EndSubSection
 SubSection "Display"
 Viewport  0 0
 Depth   4
 EndSubSection
 SubSection "Display"
 Viewport  0 0
 Depth   8
 EndSubSection
 SubSection "Display"
 Viewport  0 0
 Depth   15
 EndSubSection
 SubSection "Display"
 Viewport  0 0
 Depth   16
 EndSubSection
 SubSection "Display"
 Viewport  0 0
 Depth   24
 EndSubSection
EndSection

Copy this file to/usr/share/X11/xorg. conf. d/xorg. conf

This file ensures that the system interface can be displayed normally on the monitor when the monitor is inserted on the host computer. Next, we will add a virtual display to the system. When the host has no display, the system will use this virtual display.

Install the Virtual Graphics Driver

sudo apt install xserver-xorg-video-dummy

Add the following at the end of this file

Section "Monitor"
 Identifier "Monitor1"
 HorizSync  1.0 - 2000.0
 VertRefresh 1.0 - 200.0
 # Add 16:9 modes, others are automatically detected.
 Modeline "1280x720" 74.48 1280 1336 1472 1664 720 721 724 746
 Modeline "1920x1080" 172.80 1920 2040 2248 2576 1080 1081 1084 1118
EndSection


Section "Device"
 Identifier "Card1"
 Driver "dummy"
 VideoRam 256000
EndSection

Section "Screen"
 DefaultDepth 24
 Identifier "Screen1"
 Device "Card1"
 Monitor "Monitor1"
 SubSection "Display"
  Depth 24
  Modes "1920x1080"
 EndSubSection
EndSection

In this way, we created a virtual display using a virtual graphics card. In order for both the virtual monitor and the real monitor to work, we need to change the top ServerLayout

Section "ServerLayout"
    Identifier   "X.org Configured"
    Screen   0 "Screen0" 0 0
 Screen   1 "Screen1" 0 0
EndSection

Now restart the remote computer, and you can remotely without a monitor.

There is another problem with the above method. That is, there is no way to remotely when the user is not logged in. Therefore, you need to set the user to log in automatically.