Amazon S3 Standard-IA (Infrequent Access) | Overview.

 

Amazon S3 Standard-IA (Infrequent Access) - Overview.

Scope:

• Intro,
• S3 Standard-IA (Infrequent Access) features,
• S3 One Zone-IA,
• Comparison: Standard-IA vs One Zone-IA,
• Best Practices.

Intro:

• Amazon S3 provides specialized Infrequent Access (IA) storage classes designed for data that is accessed less frequently but still needs to be available quickly when required. 
• These classes offer lower storage costs with retrieval fees, making them cost-effective for long-lived, less active data.

 1. S3 Standard-IA (Infrequent Access)

Feature	Details
Durability	99.999999999% (11 9’s)
Availability SLA	99.9%
Minimum Storage Duration	30 days
Retrieval Fee	Yes (per GB retrieved)
Use Case	Infrequently accessed but critical data (e.g., backups, disaster recovery)
AZ Replication	Yes – stored across multiple AZs(CRR)

 2. S3 One Zone-IA

Feature	Details
Durability	99.999999999% (11 9’s)
Availability SLA	99.5%
Minimum Storage Duration	30 days
Retrieval Fee	Yes
Use Case	Infrequently accessed data that can be recreated if lost (e.g., secondary backups, logs)
AZ Replication	❌ No – stored in a single Availability Zone (SRR)
Cost	Lower than Standard-IA

 Comparison: Standard-IA vs One Zone-IA

Feature	S3 Standard-IA	S3 One Zone-IA
Availability	99.9%	99.5%
AZ Redundancy	Yes (multi-AZ)	No (single AZ)
Cost	Moderate	Lower
Durability	11 9’s	11 9’s
Use Case	Mission-critical	Non-critical, recreatable data

twtech Best Practices

• Use Lifecycle Policies to automatically transition data from Standard to IA classes.
• Avoid IA classes for frequently accessed or short-lived data (to prevent extra charges).
• Use S3 Intelligent-Tiering if access patterns are unpredictable.