Amazon S3 Glacier
Amazon S3's archive storage classes — the cheapest storage in AWS, paid for with retrieval fees and wait time.
Verified against AWS documentation · 2026-09-09
Key facts
- 01Three classes, one dial: how fast you need data back vs. how little you want to pay to keep it
- 02Glacier Instant Retrieval: millisecond access like S3 Standard-IA, 90-day minimum, cheaper to store but pricier to read
- 03Glacier Flexible Retrieval: must restore first — Expedited 1–5 min, Standard 3–5 hrs, Bulk 5–12 hrs (free), 90-day minimum
- 04Glacier Deep Archive: lowest-cost storage in AWS — Standard restore ~12 hrs, Bulk ~48 hrs, 180-day minimum
- 05Reality check: the old standalone Glacier vault service closed to new customers on 15 Dec 2025. On the exam, "S3 Glacier" means the S3 storage classes
Exam triggers
Phrases and scenarios that point here.
- "Archive", "long-term retention", "compliance", "keep for 7 years", "lowest possible cost"
- Cheapest option and hours-to-days is fine → Deep Archive; need it back within minutes → Flexible Retrieval (Expedited)
- Rarely read but must open instantly when it is → Instant Retrieval, not Flexible Retrieval
- Access pattern is unknown or keeps changing → Intelligent-Tiering, not a Glacier class
Not this service
- Unpredictable or shifting access patterns → S3 Intelligent-Tiering
- Scheduled, policy-driven backups of EBS, RDS or DynamoDB → AWS Backup
Use cases
- 01A year of CCTV footage kept for insurance disputes — Deep Archive, since you only ever pull one afternoon's clips when a claim lands
- 02Hospital imaging where a five-year-old scan might be opened mid-appointment — Instant Retrieval, because the access is rare but the wait can't be
- 03Nightly database dumps held seven years for auditors — Deep Archive; auditors give weeks of notice, so a 48-hour restore is fine
- 04A studio's finished project files where a client occasionally asks for the raws — Flexible Retrieval, restored overnight on the free Bulk tier
- 05Retiring an off-site tape rotation for DR — Flexible Retrieval restores in hours, which beats a courier driving tapes across town
How it's charged
- 01Storage per GB-month is the headline and the cheap part — Deep Archive is the lowest per-GB rate AWS sells
- 02Retrieval is billed separately, per GB restored plus per request — pulling a large archive back can cost more in one afternoon than a year of storing it
- 03Minimum storage duration is 90 days (Instant, Flexible) and 180 days (Deep Archive); delete, overwrite or transition early and you still pay the remainder
- 04Instant Retrieval bills a minimum of 128 KB per object, and Flexible/Deep Archive add ~40 KB of metadata per object — millions of tiny files erase the savings, so tar them first
- 05A restore creates a temporary S3 Standard copy you pay for on top of the archive; Bulk retrieval from Flexible Retrieval is free, Expedited is the most expensive tier
