About AFS

AFS system is designed to securely store files on central file servers. Popularly described a centrally stored file will use a cache (buffer) on the local computer to provide high speed locally. In the background the file transfer is managed continuously. - This means that it may take a short moment after the user initiated saving until the file is transfered and the application can be closed. If the transmission is disrupted or the autentification is missing - nor AFS or any other system can handle this automatically.

It is necessary to distinguish between locally stored files in the local often a laptop and  centrally stored files on the file server. Files stored on the computer network take longer time to save and some consideration must be given to this.

Some actions that the user should take to ensure the network transfer.

  • Log out. Distinguish between logging off and let the screen saver close the window. In the former case, all programs are closed and files stored in a controlled way. In the second case, the Kerberos ticket may time out and the authentication for the file system will be lost.
  • Sleep mode. If you let the computer go into sleep mode, it will sometimes not be enougth to just renew your Kerberos ticket,  wou will have to require a whole new ticket.
  • Hibernate. If you do hibernate in undocked mode, you must return in undocked mode before docking. Vice versa for the docked situation. There is a high risk the Kerberos tick times out before you restart the computer. (Hibernate means that your session and its associated files are stored locally and resurrected identical afterwards.)
  • Kerberos management. On Win7 computers there is a lock icon (bottom right edge of the hidden icons). Here you can enable the Kerberos ticket.

The following may occur (hint in italics):

  1. Documents can become invisible. The file is not visible in Explorer but you get a warning if you try to overwrite it.

    If you receive this warning, the document already exists. Save under a different filename if you want to make sure that it is saved. (You may right click the map and under afs make "flush volume".)
     
  2. You can lose control of what version of a document you are working on. If you worked on the document from different computers then one computer may open a version where recent changes are missing.

    Check contents in your document, and its modify date in explorer to make sure it is the latest version. 
     
  3. Documents can be damaged if your computer suddenly loses contact with the network.

    Wait a minute to turn off the PC (especially laptop) after closing the document. You should allways do that to allow you computer to finish all communication with the file storage. If you do not have time to wait, save on local disk.
     

AFS file system is a robust system that is used by banks, known universities such as MIT and others, and ITS has the latest versions installed.

Page Editor and Contact: Bengt-Olov Jansson

Published: 17 January 2012

Luleå University of Technology