Table of Contents Using Unix Systems from Windows
Windows and Unix are different operating systems, with different conventions. Working on Unix systems from a computer running Windows requires the installation and use of tools to connect to the Unix machines.

Logging in to the Unix System

The most basic tool required is a terminal program to log into the Unix system. ITC licenses SecureCRT. Due to security requirements, all the HPC platforms, including the Linux clusters, require the use of ssh2 to log in; this must be selected when you set up your connection to the remote machine. Here is an example of setting up a session to use ssh2 to log in to a cluster called "aspen."

It is convenient to give the connection a name, usually the name of the machine to which the connection is made (the default is "New"); it is easy to overlook the topmost field in the "new connection" screen.

Another option is the free ssh2 client PuTTY. Putty has one advantage over SecureCRT in that it can display colored text on the remote system; SecureCRT is strictly a black-and-white terminal program.

File Editing

Do not use a standard Windows editor such as Notepad to edit files that will be used on Unix systems. The two systems use different sequences of control characters to mark the end of line (EOL). If you are using the Unix machine from a Windows system, there are a number of options:
  • Log on to the cluster via SecureCRT or equivalent and use one of the many command-oriented text editors available, such as vi, emacs, pico, or jove.
  • Use NoteTab Light, available for download from Software Central. Be sure to export the file to Unix format. Then you can copy the file to the cluster via SecureFX (see Transferring Files).

  • If you have an X server for Windows, such as eXceed or equivalent, you can use the point-and-click editors gedit or nedit on the clusters.
  • If you must use a Windows-only editor, transfer the file and then apply dos2unix or flip to convert it to the correct Unix format. Type man dos2unix or man flip for more information about these commands.

    Transferring Files

    If you have the Home Directory application, you can transfer files from your home directory to your Windows desktop by dragging and dropping the file icon. You can also use SecureFX to transfer files. SecureFX opens two panes, one for your local host and one for the remote host. You can drag icons from one pane to another to transfer files.

    SecureFX has the advantage of working with all remote file locations and systems, including all temporary storage such as /bigtmp.

    The document Management and Storage of Large Files has some information about using "longtmp" temporary storage from Windows if SecureFX is not suitable for managing files on that filesystem.

    X Applications

    In order to run X (GUI) applications on your Windows system, you must install an X server. The eXceed server is a commercial X server for Windows. Exceed should be used in conjunction with SecureCRT; to do so, be sure that "X11 forwarding" is enabled in the "properties" of the connection.

    Start SecureCRT, connect to the remote Unix system, then start Exceed running in the background as a toolbar. You can then run X applications from the SecureCRT terminal.

    To run multiple applications from the terminal, append an ampersand (&) to the end of each command. This places the command into the background. See the Unix basics Web pages and Unix tutorials for more information about running commands in the background.

    Cygwin

    For those who want or need a free solution, Cygwin provides Xorg. However, Xorg is not downloaded by default when the Cygwin setup is run; the user must select it. It is also important to be sure that ssh is selected. To select X11, when the Cygwin setup.exe program is run, find Xorg in the list of packages and click on the rotation icon to change the word <">Default<"> to <">Install<">. It is not necessary to try to pick and choose among the packages, but after you have selected Xorg for installation you may open the list and select other components if you wish.

    To select ssh, go to the Net package, open the list by clicking on the box containing the plus sign, find openssh, and click on it to change the words <">Skip<"> to a version number.

    Other than these selections, you may use all defaults for the Cygwin installation.

    Once Cygwin has been installed, go to its installation directory (the default should be C:\cygwin), navigate to the bin directory, and find the startxwin or startxwin.bat file. (Whether you see the .bat will depend upon your settings.) You may right-click on its icon to bring up a menu. Select <">make shortcut<"> and then drag the shortcut to your Desktop, renaming it as desired.

    Clicking the startxwin icon will then initiate the X server. You will see a bash shell on your local machine, but the X server will be running. You can use the shell to log in to the remote machine with a command such as 

    ssh -X -l mst3k aspen.itc.virginia.edu
    where your login ID goes in place of "mst3k" and the name of the machine comes last. The -X option enables X11 forwarding under Cygwin.

    Xming

    The full Cygwin solution provides a Unix-like environment for Windows, with many tools familiar to Linux users available. For those who want only an X server, we recommend Xming . It can be used with SecureCRT or with PuTTY, but be sure that X11 port forwarding is enabled, as illustrated above for the Exceed X server.