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AFS (Andrew File System)

The AFS is a distributed network file system. Which means that any file saved inside the AFS folder will be available on every computer at EPITA.

Every student is given an AFS volume of 2 GB upon registration. The volume is deleted after the student's departure from the school (either after graduation or after drop-out).

AFS folder​

By logging in with login and password, an afs folder is automatically mounted at the root of your home folder : /home/login/afs. It is essential to understand that anything that is not located in this folder will be erased on reboot. Projects should be saved in this folder.

AFS configuration​

At account creation, plenty of configuration files are set in the .confs folder of afs : /home/login/afs/.confs/.

For configuration to be taken into account, the script /home/login/afs/.confs/install.sh is called on each session boot and deals with symbolic links in folders. For example : ln -s $AFS_DIR/.confs/bashrc $HOME/.bashrc. It is possible to add new links in this file.

Those configuration files being symbolic links, it is identical to modify /home/my_login/afs/.confs/bashrc and /home/my_login/.bashrc. To see all links, one should type ls -la in his terminal, being in his personnal folder.

It is possible to retrieve initial configuration in the folder : /afs/cri.epita.fr/resources/confs/.

Access AFS folder of an other user​

If you know the login and password of an user, you can access his afs folder from another session. It might be useful, for instance, if you can't log in your session because of corrupted config files and want to edit them using a friend account.

To get the rights to edit the content of the afs folder of an user called login, you shall follow this process :

  • Execute kinit login
  • Enter login's password
  • Execute aklog

You can then execute cd /afs/cri.epita.fr/user/l/lo/login/u/, read and edit the content of login's afs folder.

Do not forget to execute unlog and kdestroy to logout (alternatively, you may shut down the computer).

Monitoring usage​

Every AFS volume has a defined quota of 2 GB. You can check the usage of your volume by running the following command inside your AFS volume:

fs quota

To inspect the content of your AFS volume, we recommend the following command:

ncdu -x ~/afs

If your AFS volume is full, you will get the following error if you attempt to write to it: Quota exceeded. If this happens, you should clean-up your volume from unused files.

Data safety​

AFS volumes are not backed up, this means that you are responsible for the files that you store in them. In case of manipulation errors, it is not possible to restore the volume to a previous state.

To ensure the safety of your data, we highly recommend using version control systems such as Git for your ongoing projects and leverage its remote system. Intranet projects always provide remote Git repositories, and it is also possible to use EPITA's GitLab instance.