X Server Software Info
What is an X Server:
This is a program that runs on your workstation/desktop OS that 'listens' for X-Window transmissions sent from the cluster and redisplays these on your workstation. These transmissions are generated by an application running on a host that you are connected to. For example, if you intend to use Ansys on the cluster, you need to display the Ansys gui interface locally on your desktop.
What is the best supported option for users?
Contact via email tts-research@tufts.edu with your request for X11 support. Someone will get in touch with you to make arrangements for assessment and possible installation.
What X server is needed for Windows desktops?
There are many free and commercial X server programs. Cygwin is one of the free choices that works but has a more involved installation. Commercial options include Exceed, XWin32.
Cygwin X server for Windows
If I want to install Cygwin myself, where do I get Cygwin?
A&S Cygwin installation documentation can be obtained here under the X11 section.
What Cygwin programs do I install?
At a minimum, install base Cygwin, OpenSSH, and OpenGL.
What X-server solution is recommended?
Contact via email, staff@asunix.tufts.edu with your request for X11 support.
How do I connect to the cluster using Cygwin?
Open an Xterm window and connect with ssh to the head node of the cluster:
> ssh -Y -C yourusername@cluster6.uit.tufts.edu
How can I make sure Cygwin is working with the cluster?
To test the cygwin X server,try a simple cluster-side X-window application:
> xclock
A clock should appear on your desktop.
Mac X11
What X server is needed for a Mac?
An X server is either provided with Mac OS X (X11 in newer versions) or when you install the Mac X developement tools (older versions).
How can I check to see if my X server is working on my Mac?
Open up the terminal application on the Mac. At the command line type xlogo. If a small window shows up with an X in it you know X11 is working.
What happens if that doesn't work?
At the command line type xterm to start up the x11 specific terminal. If a second terminal window shows up, try the xlogo command. This will indicate that you have X installed.
What if X11 is not installed on your Mac?
Depending on the version of the operating system it is available from the installation DVD. For latest releases of OS X it is available from xquartz.macosforge.org as a package. You may also try Apple App Store.
How do I test my installation and cluster X connection?
Once you login to the cluster, type xlogo at the command line just like you did locally on the Mac. If a window with an X shows up you know X11 between the Mac and the cluster is working.
Linux X info
What X server is needed for a desktop linux user?
Linux distributions come with Xwindows which provides X server support.
How can I tell if X11 port forwarding is set up?
One way you can easily verify if X11 forwarding is set up properly is to execute the following when logged into the cluster:
> echo $DISPLAY
If X11 forwarding is set up properly then this command should display a string like "tunic6.uit.tufts.edu:xx.0". Where xx is a number, perhaps 10, 11, 12,etc... If X11 forwarding is not set up properly then it will just return a blank line.
Sometimes I get X11 related errors about the .Xauthority file, what to do?
All accounts have home directories with 500mb quotas. If you are near the limit and try to login or use X based software, you may not be able to. Clean up by deleting some files, also delete the .Xauthority file, logout and back in and you should be all set.
How does one submit a job using as input an interactive program that has a gui but not support for unattended batch submissions?
There is a command called xvfb-run that is an xwindow virtual frame buffer.
This creates an environment for the program to run the gui unattended.
For example, it is convenient to use the Mathematica notebook .nb file format as input. However this is done normally in an interactive GUI session. To simulate this X based environment use the Xvfb functionality. For example, to submit a job:
-bash-3.2$ bsub -q normal_public6 xvfb-run mathematica your_notebook.nb
Other programs may benefit as well.
Note: consider adding to your mathematica notebook the appropriate save and quit commands at the end. This will ensure proper shutdown of the application.