The following policies are in effect regarding data on SEASnet servers and on user machines that have backup support from SEASnet. These policies apply to both electronic mail and filesystem data for faculty and staff.
These policies are designed to ensure that accidentally deleted data may be retrieved, if necessary, for a reasonable period of time and provide individuals with a clear time table concerning retention of their data. SEASnet recognizes that it is important for users to know that their data is restorable in the event of accidental or catastrophic data loss, but also that data is not being retained beyond a useful period of time.
SEASnet provides snapshots of data and email maintained on our servers. "Snapshots" are taken at various intervals during each 24 hour period (see schedule below). Snapshots taken of users data files allow the user to restore data accidentally deleted from their account without intervention from SEASnet (Note: this is only possible with data files - SEASnet staff must intervene for all email restorals). SEASnet maintains approximately one to two weeks worth of snapshots. Step-by-step instructions for restoring deleted files can be found here.
| Backup Level | Frequency | Storage | Retention |
|---|---|---|---|
| Full backup | weekly at 6pm (Fri) | Tape | 3 months |
| Super incremental | daily at 6pm (Mon-Fri) | Tape | 3 months |
| Daily Full backup to disk | daily at 6am (Mon-Fri) also at 6pm (Sat,Sun) |
Disk | 2 weeks |
II. Home directories and other filesystems (including Email saved in your home directory)
| Backup Level | Frequency | Storage | Retention |
|---|---|---|---|
| Full backup | every 3 week (Sat) | Tape | 1 year |
| Super incremental | weekly (Sat) | Tape | 1 year |
| Incremental | daily (Mon-Fri) | Disk or Tape | 8 weeks |
| Snapshot type | Snapshot time | Storage | Retention |
|---|---|---|---|
| hourly snapshot | every two hours (9am-11pm) | Disk (.snapshot) | 1 day |
| daily snapshot | midnight (Mon-Sat) | Disk (.snapshot) | 8 days |
| weekly snapshot | midnight (Sun) | Disk (.snapshot) | 2 weeks |
| incremental | backs up files within a filesystem that have changed since the previous incremental backup |
| super incremental | backs up files, within a filesystem, that have changed since the last full backup of a filesystem - if utilized in conjunction with a full filesystem backup, it enables the complete restoration of a filesystem at the time of the current super incremental backup |
| full | a backup of all data within a given filesystem - it enables the complete restoration of a filesystem at the time of the current backup |
| snapshots |
snapshots are a feature of the file server used by
SEASnet to store user and electronic mail data they create virtual images of a filesystem and all data at the time the snapshot is created - this enables convenient retrieval of lost data up to the retention time of snapshots |