...
For Unix, there are several network file systems managed by the Computing Division, but we will broadly refer to their backups as NFS/GPFS/Lustre and AFS backups. NFS/GPFS/Lustre and AFS are backed up in different ways and have different backup schedules. However, there are a few underlying policies that were followed in setting up both backup systems. NOTE: not all file systems are backed up. Home directories are backed up, but most other directories are opt-in only. See below for more information.
For file systems that are backed up, NFS/GPFS/Lustre and AFS backups are performed automatically on a daily basis and should be viewed primarily as a way of recovering from hardware failures, not as an archival system. This means that the backups are not retained forever. Please see the retention period information below for each backup type.
...