About AFS-Computing Services - Carnegie Mellon University

About AFS

The Andrew File System (AFS) is the name of the distributed file system used at Carnegie Mellon.  AFS enables cooperating hosts (clients and servers) to efficiently share filesystem resources across both local area and wide area networks. Each Carnegie Mellon student, faculty and staff member is allotted AFS space; see Your Andrew Quota.  AFS is based on the UNIX operating system. To copy or rename a file, change to another directory or list your files, you will use UNIX commands.

AFS Directory Structure and Path Names

AFS uses a directory tree structure (directory, sub-directory, root). A path name is like the address of a file or directory. No two files or directories have the same path. Written out, the path name for your AFS space would be something like /afs/andrew.cmu.edu/usr#/AndrewID/ where "usr#" is between usr0 and usr25 (every user is randomly assigned to one of these directories) and "AndrewID" is YOUR personal Andrew ID (e.g., jsmith).

When you log in to AFS, you automatically enter your home directory. Your home directory was created when you first became affiliated with the university and contains a number of default subdirectories (i.e., cyrus-user, bin, private, public, www) and files (i.e., .cshrc, .login, .logout, preferences).

Cluster Related Files

In addition to the default files/subdirectories, the first time that you log in to a public cluster computer, Desktop, Documents, Downloads and Library directories are created as well as some additional files.


OldFiles, Private and Public Directories

By default, all Andrew users have a private, a public and an OldFiles directory in their AFS space. Use the private directory to save files you don't want anyone else to access. Use the public directory for files you want to share with others. See OldFiles for details on backups of your AFS files.

As was noted above, individual user volumes are organized into user groups. In the following image, notice that the users jsmith and kjones are in different user groups. However, you can remove the specific user group number from the path and your file transfer client (SSH Tectia, Fetch) will automatically find the user group for you. For example, if jsmith wants to access files in the public directory of kjones, jsmith would enter the path /afs/andrew.cmu.edu/usr/kjones/public.


Last Updated: 12/1/11