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NCSA hosts a generic linux system for use by all active users at NCSA:


This system can be accessed via SSH from anywhere and provides a useful point to:

  • test things in linux
  • public jumping point to access other NCSA systems
  • access to shared filesystems, e.g. AFS

Under the Hood


CentOS 7.x x86_64


VM, 2x 3.07GHz CPU, 4GB RAM


I can't write to my HOME directory?

  • Your home directory is stored in AFS. In order to have full permissions in your home directory, you need to have both 1) a Kerberos ticket and 2) an AFS token. You can check if you have either currently by running the following commands from the public-linux server: 

    Check for active Kerberos ticket and AFS token
  • If you aren't automatically getting a valid Kerberos ticket and AFS token upon login, you need to run the following to authenticate and obtain a new ticket and token: 

    Getting a new Kerberos ticket and AFS token

I've had an NCSA account for several years and various programs I run on the public-linux server don't work or seem out of date?

  • Older account profiles were setup with PATH environmental variables that preferred to run programs from our AFS distributed filesystem. In 2010 public-linux was reconfigured to prefer programs that were supplied by the OS distribution directly, rather than custom compiled versions of those in AFS. Running typical software from AFS is now generally discouraged in NCSA's current public-linux setup.
  • You need to update the PATH environmental variable in your profile or startup scripts.  Depending on which shell you use, you can find sample startup files at the following paths:
    • /afs/
    • /afs/
  • You can tell if your PATH environmental variable is outdated by running the following commands. If they generate output that includes "/usr/ncsa/bin", then that means you need to update your PATH:

    % which wget
    % which mysql

Getting Help

If you have any questions about the public-linux system, email .

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