Skip to content


This page has not been updated yet. The page does not reflect the transition from PBS to Slurm.


VirtualGL is an open source program that redirects the 3D rendering commands from Unix and Linux OpenGL applications to 3D accelerator hardware in a dedicated server and displays the rendered output interactively to a thin client located elsewhere on the network.

See the documentation here.


VirtualGL is available on Barbora and Karolina.

How to Use


  • VNC Server

Read our documentation on VNC server.

Warning: No xauth data; using fake authentication data for X11 forwarding.
Last login: Tue Mar  3 14:20:18 2020 from
                  ____             _
                 |  _ \           | |
                 | |_) | __ _ _ __| |__   ___  _ __ __ _
                 |  _ < / _` | '__| '_ \ / _ \| '__/ _` |
                 | |_) | (_| | |  | |_) | (_) | | | (_| |
                 |____/ \__,_|_|  |_.__/ \___/|_|  \__,_|

                  ...running on Red Hat Enterprise Linux 7.x

kru0052@login1:~$ vncserver :99

New ' (kru0052)' desktop is

Starting applications specified in /home/kru0052/.vnc/xstartup
Log file is /home/kru0052/.vnc/

  • VNC Client (your local machine)
root@toshiba:~# ssh -L 5999:localhost:5999 -X
  • Connect to a VNC server from a VNC client (your local machine)
vncviewer localhost:99

Or via GUI.


To resize the window scale, use the xrandr -s 1920x1200 command.

Run vglclient on the login server (use the terminal in the local machine VNC window)

kru0052@login1:~$ ml VirtualGL
kru0052@login1:~$ vglclient

VirtualGL Client 64-bit v2.6.1 (Build 20200228)
Listening for unencrypted connections on port 4242

Execute an interactive job on vizserv (use another terminal in the local machine VNC window)

kru0052@login1:~$ qsub -q qviz -I -A EASYBUILD -X
qsub: waiting for job 44781.isrv1 to start
qsub: job 44781.isrv1 ready


New SSH connection on vizserv - elimination of the PBS setting (use another terminal in the local machine VNC window)

kru0052@login1:~$ ssh vizserv1 -X
Last login: Tue Mar  3 13:54:33 2020 from

Run the graphical application

kru0052@vizserv1:~$ vglrun /apps/easybuild/glxgears
[VGL] NOTICE: Automatically setting VGL_CLIENT environment variable to
[VGL], the IP address of your SSH client.
libGL error: unable to load driver:
libGL error: failed to load driver: swrast
17128 frames in 5.0 seconds = 3425.573 FPS
17251 frames in 5.0 seconds = 3450.128 FPS

Examples for Remote Visualization on Barbora Cluster