Custom OS Template (Linux)

DaDesktop already provides a range of popular Linux distributions, but there are times when you need a specific distro that isn't in the current lineup. DaDesktop is glad to accommodate most mainstream Linux distros. Just let us know the download link for the ISO file and which server you’d like to use for publishing the Custom OS template.

Important:

About Disk Partitioning
1. Customized templates should stick to one disk partition or two at most: one for EFI/Boot and another for system and data.
2. LVM partitioning isn’t supported, so please avoid it.
3. An incorrect partition layout will break disk auto resize and other key features.

Linux Template

Once we pull the ISO file onto the server, you’ll find it listed under Admin Menu->OS IMAGES->ISO FILES within your account.

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

Be sure to follow this guide step by step and finish everything, or else full DaDesktop functionality might not work properly.

1. Install the OS
2. Use "student" as the default username, and set the password to "student" as well
3. Enable Auto Login for the "student" account
4. Apply DaDesktop wallpaper or your own branded background
   

5. Certain distros now come with Wayland as the default display driver. While Wayland does work inside DaDesktop, for the moment we recommend switching back to X11.
   
   To turn off Wayland:-

   edit /etc/gdm/custom.conf e.g

   # Uncomment the line below to force the login screen to use Xorg
           WaylandEnable=false
           

   sign out and sign back in

6. Install spice-vdagent—using your regular package manager is typically the best way. Note that it may already be present depending on your distribution
   • After a successful setup, reboot the machine, and you should notice two active processes: spice-vdagent and spice-vdagentd
   • 
7. Get qemu-guest-agent installed, again the easiest route is through your package manager
8. Install X11VNC. Keep in mind that for some distros, you might need to add extra repos—like the 'epel' repo for Redhat-based systems such as Oracle Linux or Rocky Linux
9. Configure X11VNC
   • confirm X11VNC is installed
   • run the command sudo -i to open a root shell

   • execute the following command so X11VNC starts automatically on reboot

     cat > /etc/xdg/autostart/x11vnc.desktop <

10. Create the desktop notify script by running the commands below

    cat > /usr/local/bin/announce-vnc-users.sh <

11. Reboot

12. Check your firewall setup, making sure TCP port 5900 is open, for example

    ss -pntl

13. Turn off the sudo password requirement (recommended)

14. Confirm everything is working

    When you connect, if the URL changes to include a token query parameter, you’re all set. That means X11VNC is functioning. Also, the text box at the bottom left of the screen, used for copy/paste between your local desktop and the virtual one, should now be operational.

Please Note

To add optional extras such as

• DDWebdav for syncing Trainer content folders to each participant machine,
• or DDUpload – a simple way to push files inside a DaDesktop machine;

Please reach out to DaDesktop Tech Support.