A hospital must retain scanned records for 10 years to meet compliance rules. Records are almost never accessed, and when auditors do request one, a retrieval time of up to 12 hours is acceptable. Which S3 storage class minimises cost for this archive?
- S3 Standard
- S3 Standard-Infrequent Access
- S3 Glacier Flexible Retrieval
- S3 Glacier Deep Archive
Correct answer: D. S3 Glacier Deep Archive
S3 Glacier Deep Archive is the lowest-cost storage class in S3 and is designed exactly for long-term retention of data accessed perhaps once or twice a year. Its standard retrieval completes within 12 hours, which matches the auditors' tolerance precisely. Glacier Flexible Retrieval restores faster but costs more per GB stored, so paying for speed the hospital does not need wastes money over a 10-year horizon. Standard-IA suits data needing millisecond access at infrequent intervals, and S3 Standard suits frequently accessed data; both are far more expensive for a decade-long archive. On the exam, match the stated retrieval tolerance to the cheapest class that satisfies it.
Source: AWS S3 docs: Amazon S3 storage classes — Glacier Deep Archive retrieval times