Custom Linux OS Template

DaDesktop keeps a range of popular Linux distributions on hand. Still, there may be times when you require a specific distro that isn’t currently available. We’re happy to support most mainstream Linux distros. Just let us know where to find the ISO file and which server you'd like to use to publish the Custom OS template.

Important:

About Disk Partitioning
1. Custom templates need only one disk partition, or two at most: an EFI/Boot partition plus a system and data partition.
2. LVM partitions are not supported – please don’t use them.
3. Choosing the wrong partition layout will prevent auto‑resizing and other features from working correctly.

Linux Template

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

Next, you can set up the template under Admin Menu->OS IMAGES->CUSTOM OS TEMPLATES

Follow this guide carefully and complete every step – otherwise, DaDesktop may not function properly.

Install the operating system
Set the default username to "student" and the password to "student"
Configure the "student" account for automatic login
Apply either the DaDesktop wallpaper or your own branded wallpaper
Some distributions now default to Wayland as the display driver. Wayland works with DaDesktop, but 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
```
Then log out and log back in.
Install spice-vdagent. Using your package manager is typically the easiest method. Note that this might already be installed, depending on your distribution.
- Once installed correctly, restart the machine. You should see two running processes: spice-vdagent and spice-vdagentd
Install qemu-guest-agent; again, your package manager is the easiest way.
Install X11VNC. On some distributions, you may need to add extra repositories, like the 'epel' repo for Red Hat-based distros such as Oracle Linux or Rocky Linux.
Configure X11VNC
- Ensure X11VNC is installed.
- Run sudo -i to open a root shell.
- Execute the following command to set up X11VNC to autostart on reboot:
```
cat > /etc/xdg/autostart/x11vnc.desktop <
```
Create the desktop notification script by running these commands:
```
cat > /usr/local/bin/announce-vnc-users.sh <
```
Reboot the system.
Check the firewall settings to ensure TCP port 5900 is open; for example, run
ss -pntl
Disable sudo password (recommended).
Verify everything is working.
When you connect, if the URL changes to a new URL containing a token query parameter, then X11VNC is functioning correctly. The text box in the bottom‑left corner of the screen, used for copy/paste between your local desktop and the virtual desktop, should now be operational.

Please Note

To include optional extras such as

DDWebdav (which syncs trainer content folders to each participant’s machine),
or DDUpload (for easy file uploads into a DaDesktop machine);

please contact DaDesktop Tech Support.