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Revision as of 13:39, 16 March 2015 by Tix11001 (talk | contribs) (Connecting Using NX)
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Running X11 GUI Apps

It is possible to run X11 GUI apps on the Hornet cluster. In general, this is not recommended and submitting batch jobs is strongly preferable. However, sometimes X11 is necessary and there are various ways to do this.

Connecting Using NX

The head node is running a NX server, so it is possible to connect with a NX client. The NX client allows you to disconnect and reconnect without crashing your apps. Note that this is beta software.

You can install an NX client (see installation instructions below) and then connect to hornet-login1.engr.uconn.edu. In your session definition be sure to specify a GNOME SESSION.

NX client for Linux

The recommended NX client for Linux is qtnx. From Debian or Ubuntu this can be installed with the command "sudo apt-get install qtnx" From Fedora, "yum install qtnx"

Connecting Using NX from OSX

The recommended NX client for OSX is OpenNX: http://opennx.net/download.html

Connecting Using NX from Windows

The recommended NX client for Windows is OpenNX: http://opennx.net/download.html Please download version FileLOpenNXConfig.png‎

Running X11 Jobs

Once you have a GUI gnome session, you can run your jobs with bsub. For a single core job which uses X11, the following will work:

  bsub -XF programname

Connection Rejected Because of Wrong Authentication Error and Solution

Make sure ~/.Xauthority owned by you

Run following command to find ownweship:

ls -l ~/.Xauthority

Run chown and chmod to fix permission problems

chown <username>:<username> ~/.Xauthority
chmod 0600 ~/.Xauthority

Replace <username>:<username> with your actual username.

Make sure X11 client forwarding enabled

Make sure your local /etc/ssh/ssh_config has following lines:

Host *
ForwardAgent yes
ForwardX11 yes

Finally, login to remote server and run X11 as follows from your Mac OS X or Linux desktop system:

ssh -X <username>@hornet-login1.engr.uconn.edu

Still cannot get X11 working

try to remove the .Xauthority file and login again:

rm ~/.Xauthority
ssh -X <username>@hornet-login1.engr.uconn.edu