Graphical Applications

Graphical Applications Using NoMachine NX

To provide for remote use of graphical applications on the cluster, we've installed NoMachine NX on the login hosts. To use it,

1. Download and install the free NX Client. (Windows users should install the optional font packages.) The NX Client uses SSH behind the scenes; see.
2. When you log in the first time, you'll see a window with a number of configuration options. Under "Desktop", choose "Unix", either "KDE" or "GNOME", and the appropriate type of connection you have to the Internet. (Users on the Argonne network should use "LAN".)

You should be able to use interactive GUIs with NX even over a DSL or cable connection. If you have problems, please contact us by clicking to send email or via telephone: 630-252-8224.

if that's not the case.

Terminating and Disconnecting

When you quit an NX session, you can either terminate it or disconnect from it. Terminating it will close all your running programs. If you discconnect you can reconnect later to the same session.

If you close the NX client window, you'll be given a choice of terminating or disconnecting.

Reconnecting

If you want to reconnect to an NX session, you'll have to log in to the same login node on which it was started. To do this, instead of using 'login.tracc.anl.gov' as the server host, specify the login node you want to connect to.

Problems

• You may see the error message "Error activating XKB configuration" when you start a new session. This can be ignored, but if you want to get rid of it, then: from the Applications menu, go to Preferences -> Keyboard, then the Layouts tab, and click Reset to defaults. This should only need to be done once.

• If the NX client stops working for you, log in with SSH, then try moving the .nx directory in your home directory out of the way:

cd; mv .nx .nx.bak

• If you get errors similar to this:

Warning: Cannot convert string "-*-courier-medium-r-*-*-*-120-*-*-*-*-iso8859-*" to type FontStruct

you need to install the optional font packages for Windows from NoMachine.

Graphical Applications Using X

xming is a convenient and easy to install X server for Windows. However, if you're doing pre- or post-processing that requires sending a lot of graphics over the network, we recommend NoMachine NX because its compression of the graphics yields a significant speed advantage over X.

To install X on a Mac, refer to this site
Mac uses XQuart to implement X applications.

Testing Graphical Applications

Connect to the ARROW cluster using ssh with either the NoMachine Graphical Application or the Graphical Application using X. Then issue the "xeyes" command.

ssh login1.arrow.tracc.anl.gov
xeyes

You should now see a graphic display of a set of eyes that can be moved around using your mouse. If this works, then your graphical application should be installed correctly.