Custom OS Template (Linux)

While DaDesktop includes several widely used Linux distributions, you might sometimes need a particular distro that isn't part of the default set. We're keen to accommodate most mainstream Linux variants. Just let us know the download link for the ISO file and the server where you'd like the Custom OS template to be published.

Important:

About Disk Partitioning
1. The custom template should have only a single disk partition, or at most two: one EFI/Boot partition and another for the system and data.
2. LVM partitions are not supported—please avoid using them.
3. An incorrect partitioning layout will break disk auto-resizing and other features.

Linux Template

Once the ISO file is downloaded to the server, you can find it in your account at Admin Menu->OS IMAGES->ISO FILES under your account.

After that, go ahead and set up the template under Admin Menu->OS IMAGES->CUSTOM OS TEMPLATES

Be sure to follow every step in this guide—skipping any could stop DaDesktop from functioning correctly.

Install the operating system
Configure the default username as "student" with the password "student"
Enable auto-login for the "student" account
Apply the DaDesktop or your own brand wallpaper
Many newer distributions now default to Wayland as the display driver. While Wayland does work inside DaDesktop, we currently recommend switching back to X11.

To turn off Wayland:-

Edit /etc/gdm/custom.conf, for example:
```
# Uncomment the line below to force the login screen to use Xorg
        WaylandEnable=false
        
```
Log out and log back in
Install the spice-vdagent package—your native package manager is usually the simplest way. Note that it might already be present depending on your distribution.
- Once installed properly, reboot the machine and you should spot two active processes: spice-vdagent and spice-vdagentd
Install qemu-guest-agent—again, your package manager is typically the easiest route
Get X11VNC installed. Note that on some distros, you may need to enable extra repositories—like the 'epel' repo for Red Hat–based systems such as Oracle Linux or Rocky Linux

Set up X11VNC

Verify that X11VNC is installed
Execute sudo -i to get a root shell

Run the following command to enable X11VNC to 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

Set up 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 system
Verify your firewall configuration—ensure TCP port 5900 is open, e.g., run

ss -pntl
Remove the sudo password requirement (recommended)
Check that everything works

When you connect, if the URL switches to one that includes a token parameter, you're all set—that confirms X11VNC is active. Also, the small text field in the bottom-left corner, used for copying and pasting between your local machine and the virtual desktop, should now be functional.

Please Note

To enable additional optional features like

DDWebdav for syncing the trainer's content folders to every participant's machine,
or DDUpload – for effortless file uploads inside a DaDesktop machine;

Please contact DaDesktop Tech Support.