Frequently Asked Questions about Computing in COS


Send comments to: S. M. Zoltek


  1. Resources Available

  2. Rules of Resource Use

  3. Getting COS Accounts

  4. How to log in

  5. Initial Password

  6. How to Change Passwords

  7. Choosing Strong Passwords

  8. Logging in Remotely

  9. Getting Windows SSH and related software

  10. Learning Unix

  11. Using email on COS machines

  12. Forwarding COS email to other accounts

  13. Obtaining Documentation

  14. Obtaining Help on System Use

  15. Reporting System Problems

  16. Software Available on Linux machines

  17. Accessing Databases from off campus

  18. Email Forwarding Problems

  19. Making Web Pages Visible

  20. Obtaining a Fortran 90 Compiler

  21. Getting pgf90/pgf77 to work on the cluster

  22. Backing Up Your COS Account on blank CDR's

  23. Getting and Installing a Freeware PC version of Latex

  1. What resources are available for use by students in COS?

    COS has Linux machines located in Science and Tech I, room 228. Access to this room is by card key 24 hours a day. Students are given a card key when they establish their computer account in COS. These machines are linked to two disk systems that have multiple Terabytes of storage. COS also has extensive computer facilities available for research.

  2. What are the rules of use for the computers in room 228? COS follows the "responsible use of computing policy" adopted for GMU. This policy explained at
    http://www.gmu.edu/facstaff/policy/administrative/60.html

  3. How do I get a computer account in COS?

    To get a computer account, you need to go to the COS office in room 103 and request a new user account form. You will be required to obtain a faculty signature for final approval. The account will normally be available within 24 hrs. At that time you may get your account name and initial password from the receptionist in room 103.

  4. How do I log in?

    Once you get your account and key card, go to room 228 and type in your user account and password at the console. If you have never used a UNIX system before, you probably need to take some of our remedial classes, CSI 601-607.

  5. What is my initial password?

    Contact the COS office, room 103, S&T I for this information.

  6. How do I change my password on the COS computers?

    To change your password on the system, you need to use the passwd command. (The system uses LDAP so your account password is the same on all the machines on the cluster.)

  7. How do I choose a strong password?

    In a terminal window, type: telnet sv01.cos.gmu.edu 129

  8. How do I log in remotely to the COS computers?

    In general, it is required to use SSH to connect to machines in room 228. SSH uses encryption to pass data between machines. Telnet, another common option for remote logins, does not. In the past, some hackers have set up "packet sniffers" to capture passwords sent by people using telnet.
    The host names for the machines in 228 are all
    wkxx.cos.gmu.edu
    where xx is the particular machine number from 01 to 16.

  9. Where do I get software for my Windows machine that allows me to use SSH?

    GMU has a university site license for the official SSH client or you can download the non-commercial version since we are a non-profit corporation. Their web site is www.ssh.com.
    http://www.irc.gmu.edu/resources/findingaid/ssh/SSH_FTP.pdf
    gives detailed instructions for downloads and installation.

    Alternatively, you can use the free program for win32 platforms :
    PuTTY - a free Win32 ssh client
    psftp - a free secure file transfer client.
    These are available at many locations on the net.

  10. How do I learn how to use Unix?

    There are number of books and on-line tutorials on Unix. However, CDS offers a set of remedial classes for people who want to improve their basic IT skills for the PhD program. CSI 601 and CSI 602 are basic introduction to Unix tools. CSI 603 and 604 are courses in programming designed for graduate students who already have some experience using other programming languages and need to learn C, C++, and Fortran 90. CSI 605 introduces some of the software development tools commonly used on Unix systems. CSI 606 and 607 teach student the basics of Oracle and IDL.

  11. How do I use email on COS machines?

    Open a browser to http://mail.cos.gmu.edu. Your email password is your SCS account password.

  12. How do I set my COS email to forward to another account?

    Create a file in your home directory named
    .forward
    Containing the address you wish to receive your email.

  13. Where do I get documentation on the software?

    COS does not maintain user documentation on the software in our machines. With the vast amount of information available on the web, it just isn't productive. Use a web search engine like google or altavista to look for on-line documentation packages you are interested in. Alternatively, you might look in the library or a book store if you really need printed documentation.

  14. How do I get help using the system?

    Talk to your instructor and other students for simple problems. Also, don't be afraid to use the web to answer questions about packages. For system specific questions that students and faculty can't answer, contact the system administrator Duane King (king@gmu.edu).

  15. How do I report problems with the system?

    Send email to king@edu and be sure to send a copy to szoltek@gmu.edu

  16. What software is available on the linux machines?

    There are literally thousands of different commands available under Unix, so it would be impossible to list them all here. However, this list gives a general overview of some of the more useful packages we have available. If you can't find something, try using "man -k keyword" to look for useful packages.
    Package Name Description Linux path
    C C language Compiler /usr/bin/gcc
    C++ C++ language Compiler /usr/bin/g++
    f77 Fortran 77 language Compiler /usr/bin/g77
    /usr/local/pgi/linux86/bin/pgf77
    f90 Fortran 90 language Compiler /usr/local/pgi/linux86/bin/pgf90
    lapack Linear Algebra Libraries /usr/lib/liblapack.a (or .so)
    blas Linear Algebra Libraries /usr/lib/libblas.a (or .so)
    perl Perl interpreter /usr/bin/perl
    python Python interpreter /usr/bin/python
    matlab Mathematics Package /usr/local/bin/matlab
    maple Mathematics Package /usr/local/bin/maple
    mathematica Mathematics Package /usr/local/bin/mathematica
    IDL Visualization
    and Data Analysis    		 /usr/local/bin/idl
    S-plus Statistics Software /usr/local/splus
    mozilla Web Browser /usr/bin/mozilla
    xpdf PDF Viewer /usr/bin/xpdf
    evince View files: pdf, ps, GIF, JPEG /usr/bin/evince
    kghostview View files: ps, pdf /usr/bin/kghostview
    ps2pdf Postscript to PDF Converter /usr/bin/ps2pdf
    xfig Drawing program for X-windows /usr/bin/X11/xfig
    OpenOffice Windows compatable
    word processor and office suite
    software    		 /usr/bin/openoffice.org-1.9
    To initially access the program
    latex Document formatting
    package    		 /usr/bin/latex
    sftp Secure file transfer
    Client and server    		 /usr/bin/sftp

  17. How do I access on campus databases from off campus?

    You need to use the GMU proxy server to access any of our commercial databases at the library. Using this service is simple. Take a look at http://infosparc.gmu.edu/lso/proxy.html for detailed information.

  18. I can't seem to get my email to forward correctly to other machines? What's wrong?

    The first thing you need to do is to create a file in your main directory named .forward , and put the full address you want the email forwarded to in this file. Make sure the file is world readable using chmod 644 .forward

  19. How do I make my web pages visible?

    First, create a subdirectory called "public_html". Create an html file called "index.html" and place it in this directory. Use the chmod command to change the permissions on both the directory and the file to be world readable. Also, you may need to change permissions on your home directory.
    The folllowing sequence of commands will set the needed permissions:

    • cd
    • chmod 711 . (Note: the 711 is followed by a space and then a "dot")
    • chmod 711 public_html
    • cd public_html
    • chmod 644 index.html

    You should be able to see this file with a web browser at http://www.cos.gmu.edu/~youraccount

    Other html files can also be added to the public_html directory. If the permissions are set correctly, you should be able to access them at http://www.cos.gmu.edu/~youraccount/filename.html

  20. Where do I get a Fortran 90 compiler for my home machine?

    There are many commercial compilers available for Linux and Windows. If you have a linux machine and are going to use the compiler for non-commerical use, intel has one you can use for free. http://developer.intel.com/software/products/compilers/flin/noncom.htm

  21. How do I get the pgf90/pgf77 compiler to work on the COS cluster?

    You need to set two environmental variables to let the license manager know where to look for the license file. You do this by setting two environmental variables, and adding the location of pgf90 to your path. You can manually type these in to make sure they work and then add them to your .bashrc or .cshrc files.

    For the default bash shell,
    PGI=/usr/local/pgi
    LM_LICENSE_MANAGER=/usr/local/pgi/license.dat
    PATH=$PATH":/usr/local/pgi/linux86/bin"
    export LM_LICENSE_MANAGER
    export PGI
    export PATH

    Using the tcsh and csh, you can use
    setenv PGI /usr/local/pgi
    setenv LM_LICENSE_MANAGER /usr/local/pgi/license.dat
    setenv PATH $PATH":/usr/local/pgi/linux86/bin"