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.

Instructions

First, you need to start the VNC server on the bwUniCluster. Therefore you must log into the bwUniCluster with your username and password as usual. You should not start the server on a login node but request an interactive job using for example the following command.

$ msub -v HOME,TERM,USER,DISPLAY -S /bin/bash -I -l nodes=1:ppn=1 -l walltime=0:02:00:00

On your assigned compute node start the VNC server with

$ module load vis/tigervnc
$ run_vncserver

If you start a VNC server for the first time you will be asked to set a password which will be required for clients trying to access your VNC desktop. Use a strong password because otherwise an attacker could take control of your VNC session. The script prints 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 TightVNC Java Viewer which is a tool that can simplify the process a little bit but needs at least Java version 1.6 to run. Therefore the next steps are divided into 3 cases. Each command should be issued on the local computer.

• Login with TightVNC Java Viewer
  Needed Software: TightVNC Java Viewer, Java
  Open TightVNC Java Viewer (the executable is called tightvnc-jviewer.jar), check "Use SSH tunneling" and fill in the parameters provided by the run_vncserver script. Now you can click on the "Connect" button and enter your passwords.

• Login without TightVNC Java Viewer for Linux users
  Needed Software: A VNC viewer such as tigervnc, gvncviewer or tightvnc
  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 TightVNC 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 viwer, 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 lateron. Please use the "log out" function of Gnome inside the VNC session, this will terminate the server properly.