S3 Standard-IA
- What it is
- Amazon S3 Standard-Infrequent Access: same millisecond access and multi-AZ durability as S3 Standard, cheaper storage, but you pay per GB retrieved.
- Numbers
- 11 nines durability, 99.9% availability, at least three Availability Zones.
- Minimum billable storage duration 30 days; minimum billable object size 128 KB.
- When to use it
- Data accessed maybe monthly but needed immediately when it is: backups, disaster-recovery copies, older logs still queried on demand.
- The trap
- Frequent access flips the math — retrieval fees can make IA cost more than Standard. Small or short-lived objects are billed as if they were 128 KB and 30 days old.
- Not to be confused with
- S3 One Zone-IA — same profile, one AZ, ~20% cheaper, not durable to AZ loss.
- S3 Glacier Instant Retrieval — cheaper storage still, higher retrieval fee, 90-day minimum.
- Exam signal
- “Infrequently accessed but must be available immediately” → Standard-IA.