Remote Desktop Tools

Overview

Remote desktop tools let you run a full graphical desktop session on an HPC system and display it on your local machine through SSH tunneling or dedicated “viewer” software. VNC is a common option for this workflow and is often more effective than X11 forwarding for visualization and other GUI-based applications that do not have a remote client/server mode (e.g., VMD). Additionally, this lets you launch the desired application directly on the compute node, allowing it to use native GPU hardware and rendering features that may be unavailable or not enabled when using applications in their remote client/server modes (e.g., VisIt).

The examples below show how to use VNC and other remote desktop tools for remote visualization on our Riker visualization cluster.

Warning

For macOS clients, it is necessary to install XQuartz (X11) to allow x11 forwarding. For Windows clients, it is necessary to install either PuTTY or an X client like Xming.

Remote Visualization using VNC

The below example is how to use VNC on Riker.

test-vnc.sh
#!/bin/sh

what()
{
   hostname
}
echo "Starting vncserver"

vncserver :1 -geometry 1920x1080 -depth 24

echo
echo
echo "**************************************************************************"
echo "Instructions"
echo
echo "In a new terminal, open a tunneling connection with $(what) and port 5901"
echo
echo "example:"
echo "   localsystem: ssh -L 5901:$(what):5901 ${USER}@riker.olcf.ornl.gov "
echo
echo "**************************************************************************"
echo
echo

export DISPLAY=:1

module load visit
visit
vncserver -kill :1

Step 1 (local system)

Install a vncviewer (turbovnc, tigervnc, etc.) on your local machine. When running vncviewer for the first time, it will ask to set a password for this and future vnc sessions.

Step 2 (terminal 1)

From an Riker connection launch a batch job and execute the below test-vnc.sh script to start the vncserver and run an executable (e.g., VisIt):

  1. localsytem: ssh -X username@riker.olcf.ornl.gov

  2. riker: salloc -A <project_id> -p gpu -t 1:00:00 -N 1 --exclusive --x11=batch

  3. riker: ./test-vnc.sh (e.g., on riker-gpu1)

$ ./test-vnc.sh

You will require a password to access your desktops.

Password:
Verify:

New 'riker-gpu1:1 (username)' desktop is riker-gpu1:1

Creating default startup script /ccs/home/username/.vnc/xstartup
Creating default config /ccs/home/username/.vnc/config
Starting applications specified in /ccs/home/username/.vnc/xstartup
Log file is /ccs/home/username/.vnc/riker-gpu1:1.log



**************************************************************************
Instructions

In a new terminal, open a tunneling connection with riker-gpu1 and port 5901

example:
     localsystem: ssh -L 5901:riker-gpu1:5901 username@riker.olcf.ornl.gov

**************************************************************************

Step 3 (terminal 2)

In a second terminal on your local system open a tunneling connection following the instructions given by the vnc start-up script (e.g., for riker-gpu1):

  • localsystem: ssh -L 5901:riker-gpu1:5901 username@riker.olcf.ornl.gov

Step 4 (local system)

Launch the vncviewer. When you launch the vncviewer that you downloaded you will need to specify localhost:5901. You will also set a password for the initial connection or enter the created password for subsequent connections.