HACC-mlcluster Enabling VNC (GUI) Access

We offer VNC support for the HACC-mlcluster development VM (unlike HACC). This means you can do GUI-based development. However, getting a GUI working will require several steps.

  1. Locally, you must install TigerVNCViewer. TigerVNC can be found at this website https://tigervnc.org/.
  2. SSH into the development VM.
  3. Open ~/.vnc/xstartup  in your favorite text editor.
    Paste the following into that file (overwriting any existing contents)      

    # Start xfce-4 Desktop 
    [ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
    [ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
    vncconfig -iconic &
    dbus-launch --exit-with-session xfce4-session &
    xhost +
  4. In the terminal, type
    Create a secure password for your VNC sessions. Note: If you do not password protect your VNC sessions, other users may be able to access your sessions! The view-only password is less important and is optional.
  5. You should receive a message telling you that a VNC session has been created. You will also be told what port that session is on. It will be in the format of a colon followed by the port number (e.g. :5). Write down or remember this port number. If you forget the port number, you can type
    vncserver –list
    to see your active sessions. Note: these sessions may close or crash. If so, you can start another by repeating step 4 (you won’t need to set the password again).
  6. Exit your SSH session.
  7. SSH back into the node, but this time add the following argument:
    -L <port_number>:<port_number>
    Where <port_number> is the value you got in step 5.
    For example,
    ssh fakeuser@ -L 5905:
    This creates a secure, encrypted tunnel which enhances the security of your VNC connection.
  8. Open up TigerVNCViewer and type the following into the VNC server field, and then press connect.
  9. Enter your VNC password.
  10. Viola! It should work now.