S3 One Zone-IA
- What it is
- S3 Standard-IA with the data stored in a single Availability Zone instead of three. About 20% cheaper.
- Numbers
- 11 nines durability within that AZ, 99.5% availability.
- Minimum billable storage duration 30 days, minimum billable object size 128 KB.
- The catch
- Destroy the AZ and the data is gone. There is no cross-AZ copy to fall back on.
- When to use it
- Data you can recreate: thumbnails, transcoded media, derived datasets, or a secondary copy of a backup that also lives elsewhere.
- Exam signal
- “Re-creatable”, “can tolerate the loss of one AZ”, “cheaper infrequent access” → One Zone-IA.
- Anything described as irreplaceable → never One Zone-IA.