ITS General Computing

AFS (Andrew File System) FAQ

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What is AFS?

The Andrew File System (AFS)—also known as Institutional File System (IFS)—is a central file storage, sharing, and retrieval system that you can access from Windows, Macintosh, and Unix computers. It is derived from the Andrew File System developed at Carnegie-Mellon University. AFS lets you access your documents and files from different computers at different locations.

Members of the U-M community can access their AFS space via the web using MFile. For more about AFS, see AFS Overview.

How do I get an AFS home directory?

Faculty, staff and students affiliated with the College of Engineering automatically receive a 10GB AFS home directory as part of their standard computing services. Other members of the U-M community who are eligible for standard computing services may choose to use the AFS Self-Provisioning Tool to receive a 10GB AFS home directory or to verify they already have one. That home directory can be used to store and share files and to publish personal Web pages. For information about AFS, see AFS Overview.

Group directories are also available. See "How do I get AFS space for a class, group, or campus organization?" for details.

Can I get to AFS via the web?

Yes! You can use MFile to work with the files in your AFS home directory. It can also be used to access group home directories. See Using Your AFS Home Directory Over the Web with MFile for details.

What is the AFS host name?

For file transfer connections (SFTP), use this hostname:

How do I publish a web page using my AFS home directory?

You can publish your own home page on the web by using the Public folder inside your AFS home directory. Create a folder called html inside your Public folder, and put your web page inside. For more detail, see How to Create Your Own Home Page.

You can also publish a web page or site using your AFS home directory that is restricted to members of the university community—or to some group of people at U-M that you specify. See Restricting Access to Your Web Pages for details.

How do I find out how much AFS space I have left?

As part of your standard computing services, you have the option to self-provision yourself to receive file storage space in AFS. To find out how much of your space you are using and how much you have left, do the following:

From the ITS Login Service

How do I get more AFS space?

To get additional group storage space in AFS, contact the ITS Service Center.

How do I connect to AFS?

Use Secure File Transfer Protocol (SFTP) software to connect to AFS for downloading and uploading files.

How do I get AFS space for a class, group, or campus organization?

You can arrange to have a group AFS directory—to use as a shared work space, as a means of publishing on the web, or for some other purpose—for your department, unit, or student organization. Also, faculty members can have an AFS group directory for a class that they teach.

How do I give someone access to a group directory so they can make changes to the group's web pages?

See this documentation:

How do I access backups of my files in AFS?

All the files in the Andrew File System (AFS) are backed up regularly by ITS for your security and convenience.

Should you accidentally delete, change or otherwise destroy files in your AFS home directory, there are two ways you can get the files restored from the backups:

For details, see Using AFS Backup and Restore Services [Oldfiles and Operator Restores].

How do I control access to my files (set permissions) in AFS?

Restricting Access to the U-M Community

Pages that you publish on the web are normally available to anyone who browses the web. You can, however, restrict access to your web pages to the U-M community or to groups and/or individuals within it. Those who wish to view your pages must first log in with their uniqname and UMICH password. See Restricting Access to Your Web Pages for details.

Restricting Access to Specific Individuals or Groups at U-M

You can control whether other people can see the files and documents in the folders inside your AFS home directory, whether they can make changes to them, and more in two ways:

htaccess files, Access Control Lists (ACLs), and pts Groups

An ACL is a list of uniqnames and/or protection groups to which access rights have been assigned. (A protection group—or pts group—is similar to an email group except that it is a list of uniqnames rather than a list of email addresses; it is used to assign permissions to a group of people. ACLs are set for folders.

See the Restricting Access to Specific Groups and Individuals at U-M section of Restricting Access to Your Web Pages for details.

htaccess Files and Directory Groups

You can restrict access to your web pages to the members of specified LDAP groups in the MCommunity Directory. See Using Web-Authenticated Resources (Weblogin Using Cosign) at U-M for details.

How is AFS organized?

To learn about the file structure of AFS, see the Navigating AFS section of AFS Overview.

What does the error message "Remote scp disabled on this host" mean?

If you try to open an SFTP connection to the Login Service (to access your AFS space) by using the address, you will receive this error message: "Remote scp disabled on this host."

This is because you must use a different address for SFTP connections. Please connect to for SFTP connections to access your AFS space instead.

My question about AFS isn't in this list. Who can I ask for help?

The ITS Service Center can answer your questions about AFS and transferring files at U-M.

These services are available to members of the University of Michigan community only.