Simple definition
Grandfather-Father-Son (GFS) retention keeps selected backups across daily, weekly, monthly and sometimes yearly intervals.
Technical definition
GFS is a backup-retention policy rather than a backup method. It retains restore points at different frequencies so organizations can restore recent changes while also keeping older points. Exact retention behavior and storage usage depend on the backup product and whether it uses full, incremental or synthetic backups.
What is it used for ?
Balance long-term recovery requirements with storage consumption and retention policies.
Practical example
For example, a policy could retain daily backups for one week, four weekly recovery points, 12 monthly points and seven yearly points, if supported by the backup solution.
Common issues
- Undersized retention
- Poorly estimated storage capacity
- Confusion between GFS and regulatory archive
Related terms
Key takeaway: Exact behavior and commands may vary depending on versions, products and architectures.