Amazon S3 - Glacier Storage Classes | Overview.

Amazon S3 - Glacier Storage Classes - Overview.

Scope:

• Intro,
• three Glacier storage classes,
• S3 Glacier Instant Retrieval,
• S3 Glacier Flexible Retrieval (previously just S3 Glacier),
•  S3 Glacier Deep Archive,
• Summary Table.

Intro:

• Amazon S3 offers Glacier storage classes for archival and long-term data storage at very low costs. 
• These are ideal for data that is infrequently accessed but must be retained for compliance or backup purposes.

There are three Glacier storage classes:

1. S3 Glacier Instant Retrieval

• Use case: Archival data that needs immediate access (milliseconds latency), such as medical images or news media archives.
• Retrieval time: Milliseconds
• Cost: Higher than other Glacier classes, but still cheaper than Standard storage.
• Minimum storage duration: 90 days

2. S3 Glacier Flexible Retrieval (previously just S3 Glacier)

• Use case: Long-term storage where retrievals are rare but occasionally needed.
• Retrieval time:
• Expedited: 1–5 minutes
• Standard: 3–5 hours
• Bulk: 5–12 hours
• Cost: Lower than Instant Retrieval, with options for cost-effective retrieval tiers.
• Minimum storage duration: 90 days

3. S3 Glacier Deep Archive

• Use case: Lowest-cost storage for data rarely accessed, such as compliance archives, digital preservation, and backups.
• Retrieval time:
• Standard: 12 hours
• Bulk: 48 hours
• Cost: Lowest of all S3 storage classes
• Minimum storage duration: 180 days

twtech Summary Table.

Storage Class	Retrieval Time	Use Case	Min Duration	Relative Cost
Glacier Instant Retrieval	Milliseconds	Frequent/occasional access	90 days	Low
Glacier Flexible Retrieval	Minutes to hours	Rare access	90 days	Lower
Glacier Deep Archive	12–48 hours	Very rare/long-term access	180 days	Lowest