NoMachine Setup for Headless Server - norlab-ulaval/Norlab_wiki GitHub Wiki

This is a quick tutorial to setup a NoMachine VNC instance on Ubuntu 22.04. Note that doing these steps will make the X Server run in headless mode, meaning that connecting an external display will not work anymore. It is still possible to connect a screen if you connect it before Linux boots.

Installing NoMachine

To install NoMachine, download and follow the instructions here. It should enable a service to launch it automatically on startup, so all good on that side.

Configure X Server as headless

Since we want to display the computer's screen, but there is none, we need to configure Linux to run as "headless", meaning that it will create a dummy monitor for itself. To do that run the following:

sudo apt update
sudo apt install xserver-xorg-video-dummy x11-xserver-utils

Then, write the following to the file /etc/X11/xorg.conf:

Section "Monitor"
    Identifier   "Monitor0"
    HorizSync    28.0-80.0
    VertRefresh  48.0-75.0
EndSection

Section "Device"
    Identifier  "Device0"
    Driver      "dummy"
    VideoRam    256000
EndSection

Section "Screen"
    Identifier "Screen0"
    Device     "Device0"
    Monitor    "Monitor0"
    DefaultDepth 24
    SubSection "Display"
        Depth    24
        Modes    "1920x1080"
    EndSubSection
EndSection

Section "ServerLayout"
    Identifier "Layout0"
    Screen 0 "Screen0"
EndSection

Finally, to make the headless X server start automatically, create a systemd service.

sudo nano /etc/systemd/system/headless-x.service

And add the following content:

[Unit]
Description=Headless X Server
After=multi-user.target

[Service]
ExecStart=/usr/bin/X :0
User=<your_username>
Restart=always

[Install]
WantedBy=multi-user.target

Then enable and start it:

sudo systemctl enable headless-x
sudo systemctl start headless-x

Test connection

Install NoMachine on your own computer and try to connect to your headless server. Press ADD in the top left corner, give a name to the remote computer, enter its IP address and confirm with ADD. Make sure you are on the same network and double-click on the device icon to connect to it. Enter the user's credentials and check the box to memorize it for later.

USB Forwarding

If USB forwarding is not working (no devices are displayed), follow this guide to install the kernel module: https://kb.nomachine.com/AR12J00658