Athena Server Operations AFS Backup Policies
The following policies pertain to the production AFS cells (athena and dev) maintained by Athena Server Operations (ASO). Other test cells may have fewer backups (eg. ops cell), or no backups at all (eg. zone cell). Additionally, the following policies do not apply to volumes or lockers that are designated as non-backed-up.
ASO guarantees to have at least one backup from every two week interval for the last six months. ASO actually makes backups more frequently than this, but some are only kept for a short period of time. When a backup is no longer needed, either because it is older than 6 months, or because there are enough other backups from the same time period, ASO will recycle or destroy the tape or hold it for future re-use or destruction at their discretion.
In addition to the regular backups, ASO makes an "archival" backup twice a year, shortly after the end of each term. Archival backups may include volumes and lockers that are designated as non-backed-up. These backups will be kept for a minimum of 5 years. Like the regular backups, once "archival" backups are old enough they may be recycled, destroyed or held.
If at any point in the life of a backup ASO no longer has the necessary tools to read a backup, that backup will be immediately eligible for re-use or destruction, regardless of the above policies.
The primary purpose for all of the above backups is to recover from hardware failures and other systemic events. However, in cases of data accidently lost by a user ASO will make a reasonable effort to help recover the data.