Install X Windows

How to Install and Use an X Windows Server to Access Lewis:

  1. Please note that an X windows server should only be used to access Lewis when one needs to run an interactive job, e.g., one that generates a graphical user interface (gui).  If your job is not interactive and does not require X windows then please log into the Lewis head node using a program such as SSH Secure Shell (found at Accessing Lewis).  Non-interactive jobs will generally run faster if one uses LSF through the head node of Lewis.

  2. Since MS Windows operating system does not come with support for the X Window System (the networking and display protocol for unix and unix-like operating systems) MS users must install their own support to see the graphical display generated by certain programs on Lewis (e.g., Genesis, MapMan).  Download the free Cygwin/X Server.  (It is probably not the only free X server, just the one we are most familiar with). The directions for download and installation may be found here.  Default settings will work to install Cygwin/X correctly.  However, it is important to request the correct packages from the mirror site.  These are obtained at the step when the Cygwin Setup/Select Packages window is displayed.  Click the "View" button in that window to expand the list of packages.  Scroll down to find the xorg-x11-base package and click on the box under the column marked Bin.  Several boxes that support that package will also then become checked.  Then find and check under column Bin the package called openssh: The OpenSSH server and client programs.  When both these are checked then proceed.

  3. If you have installed Cygwin correctly the icon should be on your desktop.  Clicking on that will open a window with the Cygwin logo on it.  At the command prompt type startxwin.sh.  A Cygwin/X error message may appear.  It may be ignored so long as another window has appeared.

  4. The other window should have a large X at the top.  In the command line of that window type ssh -X lewis.rnet.missouri.edu -l userid and hit return.  (Note: if you will edit your files using emacs, then substitute -Y for -X).  Enter your password.  You should see your home directory on Lewis.

  5. You are now almost ready to initiate the program of interest (Genesis, MapMan, or some other).  Normally for an interactive program on Lewis one would run "lsrun -P program_command args".  At present that does not lead to a graphical display.  Instead of using lsrun enter the commmand gocomp and hit return.  This will take you to a compute node on Lewis that is designated for interactive sessions.  Once you have done this execute the command for your program and the graphical display should appear.  You will not need lsrun for this execution either.  If you execute your program without using gocomp first you will not see a display.  You will also remain on the "head" node, where you will be a nuisance to all other users, and performance will be less.