Amazon S3 Storage Classes : Infrequent Access Storage Class

 

Amazon S3 Storage Classes: Infrequent Access (IA)

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.