AFS Basic Usage

Basic Usage

When you login to a CSAIL Ubuntu machine or have AFS installed and setup correctly on Windows or Mac, you obtain a “token” that verifies your identity to the file system. This token has a lifetime of 10 hours. If your token expires you lose access to your AFS directories.

To check if you have a token, type:


To obtain a new token, type:


To create your Kerberos ticket, type:


If you remain logged-in to a computer for over 10 hours you may find that the computer won’t let you write to your own files. This is because your token has expired, or you may have lost network connection or been timed out. Run

kinit && aklog

(or, equivalently, our convenience script renew, which is probably in your $PATH).

Long-running jobs

If you require credentials which last longer then 10 hours, please see the longjob, longscreen, or longtmux command. You can get more info by simply running the commands with -h or --help:

longjob -h
longscreen -h
longtmux -h
More information about these commands...

On a CSAIL Ubuntu machine these should already be in your $PATH; they’re in /usr/local/csail/bin (as is the renew script mentioned above).

AFS quotas

By default, most volumes are set initially at 20G. If you, your group, or project requires more personal storage than this, please contact

To list your volume quota, type:

fs listquota