Custom OS Template (Linux)

While DaDesktop offers a wide selection of popular Linux distributions, sometimes you may need a specific one that isn't already on the list. We're glad to help with most mainline distros. Just let us know the download location for the ISO file, and the server where you'd like the Custom OS template to be published.

Important:

About Disk Partitioning
1. Your customized template should have only one 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 LVM
3. Using the wrong partition scheme will prevent disk auto-resize and other features from working properly.

Linux Template

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

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

Make sure to follow this guide closely and complete each step—otherwise DaDesktop may not function correctly.

1. Install the OS
2. Set the default username to "student" and the password to "student"
3. Configure the "student" account for automatic login
4. Apply the DaDesktop or your own brand wallpaper
   

5. Many distros now default to the Wayland display driver. While Wayland does work in DaDesktop, we currently recommend switching back to X11.
   
   To disable 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

6. Install spice-vdagent—using your package manager is generally the easiest way. Note that it might already be present on your system.
   • After a successful installation, restart the machine. You should see two running processes: spice-vdagent and spice-vdagentd
   • 
7. Install qemu-guest-agent—again, using your package manager is recommended.
8. Install X11VNC. Note: For some distributions, you may need to enable additional repositories—like the 'epel' repo on Red Hat–based systems such as Oracle Linux or Rocky Linux.
9. Configure X11VNC
   • ensure X11VNC is installed
   • run sudo -i to open a root shell

   • run the command below to have X11VNC auto-start on reboot

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

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

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

11. Restart the machine

12. Check your firewall settings—make sure TCP port 5900 is open, for example:

    ss -pntl

13. Disable the sudo password (recommended)

14. Confirm everything is working

    When you connect, if the URL changes to include a token query parameter, you're all set—that indicates X11VNC is serving the session. The text box at the bottom left of the screen, used for copy/paste between your local machine and the virtual desktop, should now function correctly.

     

Please Note

If you'd like to add optional features such as

• DDWebdav, which synchronizes the trainer's content folders with each participant machine,
• or DDUpload, for easy file uploads into a DaDesktop machine;

Please contact DaDesktop Tech Support.