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Remote visualisation

Remote Visualisation

This guide describes the ARC remote visualisation service, which enables users to run a graphical application on any of the ARC systems, while visualising the result on their own device (desktop, laptop or even smart phone).

Remote visualisation on the ARC systems is possible by establishing a link to oscgate.osc.ox.ac.uk via NoMachine, a commercial visualisation tool that handles remote X window system connections.  The NoMachine link provides a convenient, high-performance method of running a graphical desktop on one of the ARC systems (through oscgate) from your local client system.  The method ensures near local speed application responsiveness over high latency, low bandwidth network and is in most cases more suitable than a simple remote link (e.g. through ssh).

This short guide describes the use of NoMachine for connecting to the ARC and is intended for a "quick-start" use.  More educational material can be found on the NoMachine support page.

 

Preliminaries

To establish the NoMachine link, both a NoMachine server and a NoMachine client are needed; oscgate.oerc.ox.ac.uk is already running the server.

Users need to install a NoMachine client on their device.  Visit http://www.nomachine.com/download to download a client package suitable for your desktop.  Installation packages for Linux, Mac OSX and Microsoft Windows can also be found here.

 

Connecting

Once the NoMachine client installed, the connection with oscgate.oerc.ox.ac.uk can be established.  Using the client is simple and intuitive, so this guide does not provide detailed guidance.  However, step-by-step general guidance (including a FAQ and tutorials) can be found, if needed, on the NoMachine support page.

Once the client wizard started, a "connection" can be created; this stores the details of the link to oscgate.  In essence, this involves choosing ssh as the connection protocol (rather than the proprietary NoMachine NX) and providing the DNS entry for oscgate, as see in the following two screencasts:

 

Choose the system login authentication method (the default option) using password and opt for a non-proxy network connection.  Lastly, name and save the "connection".  The "connection" then appears every time the client wizard is started, as shown below:

 

To establish the link, users should click on the "connection".  A host authenticity warning page appears the first time a link to oscgate is attempted, as ssh asks the user to confirm connection continuation.  The NoMachine wizards prompts the user for the username and password, for which the ARC credentials should be used.

 

The last operation after authentication is the creation of a virtual desktop, with various options, such as screen size and resolution, all of which can be saved for subsequent use.  Finally, the link to oscgate is established, with a screen that shows user directories and files in $HOME:

 

Visualising

Once the link to oscgate established, users can open up a terminal in order to connect to an ARC system for visualisation:

 

A simple example is loggin to the Arcus headnode to plot some results in Matlab.  Notice the connection from oscgate to Arcus is done via ssh -Y arcus; without -Y, any graphics will not work.

 

Once visualisation is finished, users can quit by clicking on their username (upper right corner) and selecting Quit.