JUSTUS2/Visualization

TigerVNC

TigerVNC
module load	vis/tigervnc
License	GPL
Links	TigerVNC Homepage

TigerVNC is a high-performance implementation of VNC (Virtual Network Computing), a client/server application that allows users to launch and interact with graphical applications on remote machines. It should be faster than standard X11 forwarding and thus can be used if a graphical software feels slow and has bad responsiveness.

Start

First, you need to start the VNC server. The exact startup mechanism depends on the cluster.

• Start VNC Server - bwUniCluster
• Start VNC Server - bwForCluster Chemistry
• Start VNC Server - bwForCluster Chemistry - 3D Acceleration

Login

The startup script of the VNC server should print detailed instructions on how to establish the connection to the VNC server from your local computer. They depend on whether you use Windows or Linux and if you work with TurboVNC Java Viewer which is a tool that can simplify the process a little bit but needs the Java Development Kit (JDK) to run. Therefore the next steps are divided into 3 cases. Each command should be issued on the local computer.

• Login with TurboVNC Java Viewer
  Needed Software: TurboVNC 2.0 Beta, JDK
  Open TurboVNC Java Viewer (the executable is called VncViewer.jar). Go to Options... -> Security -> Gateway and fill in the parameters provided by the run_vncserver script. You can save these settings in the "Global" tab if you want to. Now you can click "OK", supply the VNC server and connect to the server. You should be prompted for your ssh password and your VNC password and after that the connection is established.

• Login without TightVNC Java Viewer for Linux users
  Needed Software: A VNC viewer such as tigervnc or turbovnc
  A tunnel must be created with the ssh command given by the run_vncserver script. Open a new terminal, start a VNC viewer and connect to localhost:n, where n is the display number printed by run_vncserver, using a command such like this
  

  $ vncviewer localhost:1

• Login without TurboVNC Java Viewer for Windows users
  Needed Software: tigervnc, Putty
  You need to start Putty and go to Connection -> SSH -> Tunnels. Choose "IPv4" and fill in the parameters provided by run_vncserver. After you clicked "Add" you must navigate to Session and connect to the bwUniCluster with your username and password. Once the connection is established start the tigervnc client and connect to localhost:n where n is the display number printed by run_vncserver.

Shutdown

To exit your VNC session it is not sufficient to only close the window of the viewer, because this will not terminate the VNC server. The server will keep running and you will run into problems when you try to start a new VNC session later on. Please use the "log out" function of the desktop environment inside the VNC session, this will terminate the server properly.

Starting OpenGL programs

Starting an OpenGL program in a 3D accelerated VNC session results in an error message. In order to fix this issue and redirect OpenGL commands to the graphics card on the cluster you have to use the vglrun command like in the following example:

$ vglrun glxgears -info