Linux Custom OS Template

DaDesktop already offers several popular Linux distributions, but occasionally you might need one that isn't included. In Romania, we're pleased to support this for most mainstream distros. Just let us know where to download the ISO file and the server you'd like to use for publishing the Custom OS template.

Important:

About Disk Partitioning
1. Custom templates need just one disk partition, or at most two: an EFI/Boot partition and a separate system and data partition.
2. LVM partitions are not supported—so steer clear of LVM.
3. An incorrect partition layout will prevent disk auto-resize and other features from functioning properly.

Linux Template

Once we've downloaded the ISO file to the server, you'll find it in your account under Admin Menu->OS IMAGES->ISO FILES in your account.

After that, you can set up the template from Admin Menu->OS IMAGES->CUSTOM OS TEMPLATES

Please follow this guide carefully, and complete all the steps as otherwise full DaDesktop operation is likely not to work.

Install the operating system
Set the default username to "student" and password to "student"
Configure the "student" account for automatic login
Apply the DaDesktop wallpaper or your own branded one
Many distros are now set to use Wayland by default as their display driver. Even though Wayland works with DaDesktop, we suggest reverting to X11 for the time being.

To disable Wayland:-

edit /etc/gdm/custom.conf e.g
```
# Uncomment the line below to force the login screen to use Xorg
        WaylandEnable=false
        
```
log out and log back in
Install spice-vdagent, typically best done via your package manager. Note that it might already be present, depending on your distro.
- Once installed correctly, reboot the machine; you should then see two active processes: spice-vdagent and spice-vdagentd
Install qemu-guest-agent; once again, using your package manager is the recommended method
Install X11VNC. For some distros, you might need to add extra repositories—like the 'epel' repo for Red Hat–based systems (e.g., Oracle Linux or Rocky Linux).

Configure X11VNC

Ensure X11VNC is installed
Run sudo -i to open a root shell

Then run the command below to make X11VNC start automatically on reboot

cat > /etc/xdg/autostart/x11vnc.desktop <<EOF
                [Desktop Entry]
                Type=Application
                Exec=/usr/bin/x11vnc -N -no6 -rfbportv6 -1 -allow 10.0.3.1 -nopw -shared -alwaysshared -forever -repeat -nowireframe -noscr -nocursorshape -skip_lockkeys -cursor_drag -grab_buster -deferupdate 10 -speeds 6000,5000,20 -afteraccept announce-vnc-users.sh -gone announce-vnc-users.sh
                Hidden=false
                X-MATE-Autostart-enabled=true
                X-MATE-AutoRestart=true
                Name[en_US]=X11VNC
                Name=X11VNC
                Comment[en_US]=Share desktop over VNC
                Comment=Share desktop over VNC
                EOF

Create the desktop notification script by running these commands

cat > /usr/local/bin/announce-vnc-users.sh <<EOF
        notify-send -a x11vnc "VNC users connected: $RFB_CLIENT_COUNT"
        EOF
        chmod +x /usr/local/bin/announce-vnc-users.sh

Restart the machine
Verify the firewall settings: ensure TCP port 5900 is open. For example, run

ss -pntl
Disable the sudo password (recommended)
Verify success

To verify, connect to the machine. If the URL changes to include a token query parameter, you're all set. That indicates X11VNC is functioning correctly. The text box in the bottom-left corner, which handles copy/paste between your local and virtual desktops, should also be operational now.

Important Note

To add optional extras such as

DDWebdav, which syncs the trainer's content folders to each participant's machine,
or DDUpload, for easy file uploads to a DaDesktop machine;

Please get in touch with DaDesktop Tech Support.