Amazon S3 Glacier Storage Classes.

 

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