VNC REMOTE ACCESS TO PBIC CLUSTER FROM A PC

VNC (Virtual Network Computing) is remote control software which allows you to view and interact on one (server) computer from another (client) computer that may be physically located somewhere else, anywhere on the internet. The client computer needs to use client viewer software like SSVNC. The remote server computer needs to use a server program version of VNC usually called vncserver. SSVNC is the enhanced TightVNC Viewer which adds encryption security to VNC connections. The two computers don't have to be the same type, so typically you would use SSVNC running on your Windows PC in your office or at home to connect to a Linux workstation running vncserver on the PBIC Cluster.

SSVNC automatically starts up an SSL tunnel for SSL or ssh/plink for SSH connections to any VNC server, such as x11vnc, and then launches the VNC Viewer to use the encrypted tunnel.

In the PBIC cluster, the workstation on which you can run vncserver is pbic.bham.ac.uk.

The client machine is your local PC, Mac or Linux machine.

 

Download and install packages

You will probably also find it useful at this time to download WinSCP. This program allows you to copy files between the remote workstation and your local PC. WinSCP can be installed or an executable version is also available.

To use SSVNC on a windows PC you will need to download SSVNC client viewer program. You can download the SSVNC viewer  64bit package from here. PuTTY (a Windows SSH client) is also included in this package. Once downloaded and extracted, to make access easier, make a shortcut to the PuTTY executable from your desktop

\ssvnc\Windows\util\putty.exe

To run SSVNC the following batch file can be run or a shortcut copied to your desktop:

\ssvnc\Windows\sshvnc.bat    

Using PuTTY to start vncserver session

Double click on putty.exe and in the session window enter pbic.bham.ac.uk in the Host Name section. Ensure connection type SSH is selected and click on open:

 

 

 

 

 

Enter your University ADF username and password when prompted.

Once successfully connected through PuTTY enter the following at the command prompt to start a VNC session:

vncserver

You may want to override the default desktop size (the default is 1024x768) to match your local desktop screen or laptop size. If, for example, you wanted a larger screen size of 1280x1024, amend the command as follows:

vncserver -geometry 1280x1024

You may want also want to override the default color depth (16 bits) to be 24 bit color:

vncserver -depth 24

Or you may want to do both at the same time:

vncserver -geometry 1280x1024 -depth 24

Note that you should only run the vncserver command once, the first time you connect to pbic.bham.ac.uk. Only if the vncserver session crashes or if the PBIC Cluster is rebooted should you run this command again. If you do already have a vncserver session running, do not try and run another server session. You should get a warning telling you that you already have a session running (and telling you which session number it is). If you do start multiple sessions, the later ones will be killed automatically.

If you have never run the vncserver before you will be prompted twice to set a password. To avoid later confusion it would be sensible to make this password the same as your regular University ADF login password.

When you run the vncserver command it will show the display name and number of the VNC session in the form:

pbic.bham.ac.uk:XX

 

where XX is a one or two digit number. This is the display number of the virtual desktop.

Make a note of the XX number - it is your unique VNC session identifier.

You may now type "exit" to close the SSH session (or click "x" button on top right of window to close the PuTTY window). The remote vncserver session you have started will stay running. So long as the remote computer pbic.bham.ac.uk is not rebooted, this virtual session will continue to run until you choose to kill it.

 

Running SSVNC client

When you run the sshvnc.bat script the following screen should be displayed:

 

Enter your University ADF username, the remote server name and VNC session number in the field called VNC Host:Display using the following format where XX is the vncserver display number started earlier in Putty:

username@pbic.bham.ac.uk:XX

 

 

 

If the connection is successful the following screen will be displayed requesting you enter your University ADF password:

 
 

If you have successfully entered your University ADF password the following login screen will appear, you will now need to enter your VNC password set when you first started your vncserver session:

 

 

Your SSVNC session should now start.

You will need to run SSVNC in the same way from now on to connect to your VNC session (Putty is no longer required unless you need to restart your vncserver session again).

 

Finishing a VNC session - Leaving the VNC server running

If you wish to close the connection to pbic.bham.ac.uk close only the SSVNC viewer window.

When you reconnect to this VNCServer session again, you only need to connect using SSVNC.

To close the SSVNC window click on the "x" button in the top right hand side of the window.

 

IMPORTANT - You should not LOG OUT using the system menu "System -> Log Out user". This will leave the session unaccesable and will need to be killed (using vncserver -kill as below).

 

Finishing a VNC session - Shutting down the VNC server

Should you not need to keep the session alive then you should stop your vncserver to free up resources for other users. This can be done by using a PuTTY connection to pbic.bham.ac.uk as above and then typing:

vncserver -kill :XX

where XX is your display number.


Useful VNC commands

 

vncserver -geometry 1280x1024 Start vncserver with specified display size
vncserver -depth x24 Start vncserver with specified screen colour depth
vncserver :xx Start specified vncserver session number
vncserver -kill :xx End specified session number
vncpasswd Change vncserver password
vncwho List all running vncserver sessions