S3 Review and Storage Classes

Learning outcomes

By the end of this lesson, you will be able to:

1. Explain what Amazon S3 is and what it does.
2. Explain what an S3 storage class is.
3. Choose a sensible storage class for common scenarios.
4. Distinguish between frequently accessed, infrequently accessed, and archival S3 data.
5. Explain how S3 Lifecycle can move objects between storage classes over time.

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How S3 storage classes work

S3 is where you store files and objects, and storage classes let you choose the right cost/performance tradeoff for how often that data is accessed.

A simple memory rule:

• S3 Standard for active data.
• IA classes for infrequently accessed data.
• Glacier classes for archive data.
• Intelligent-Tiering when you are not sure how access will change.

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1) S3 in One Sentence

Amazon S3 (Simple Storage Service) is AWS's object storage. It stores data as objects (files + metadata) inside buckets (containers). It is the go-to service for web assets, user uploads, backups, and data lakes.

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2) Main Storage Classes

A) S3 Standard

The default class. Designed for general-purpose storage of frequently accessed data.

• Use case: Website assets, active application files, images users access daily.

B) S3 Intelligent-Tiering

Automatically moves your data between access tiers to save you money. It is the only cloud storage class that delivers automatic cost savings when access patterns change.

• Use case: Data with unknown or changing access patterns.

C) S3 Standard-IA (Infrequent Access)

For data that is accessed less often but requires rapid (millisecond) access when needed.

• Use case: Backups you might need quickly, older documents still needed occasionally.

D) S3 One Zone-IA

Similar to Standard-IA but stores data in only one Availability Zone.

• Use case: Easily recreated data (like thumbnails) where you can handle the loss of an AZ.

E) S3 Glacier Instant Retrieval

Archive storage for data that is rarely accessed (once a quarter) but still needs to be available in milliseconds.

• Use case: Medical records or media assets that are rarely opened but must load instantly.

F) S3 Glacier Flexible Retrieval

For archive data that doesn't need immediate access. Retrieval can take minutes to hours.

• Use case: Backup data used for disaster recovery.

G) S3 Glacier Deep Archive

The lowest-cost storage class. Retrieval takes 12-48 hours.

• Use case: Compliance records or data you almost never expect to open.

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3) A Note About S3 Express One Zone

AWS also offers S3 Express One Zone, which is designed for very frequent, latency-sensitive access (like machine learning or high-performance computing) within a single Availability Zone. While powerful, you should focus on the classes above first.

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4) Important Tradeoffs

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5) S3 Lifecycle Policies

S3 Lifecycle can automatically transfer your data to a different storage class or delete it after a certain period. This helps you optimize costs without changing your application code.

A common lifecycle pattern:

1. 0-30 Days: S3 Standard (Active use)
2. 30-90 Days: S3 Standard-IA (Infrequent use)
3. 90+ Days: S3 Glacier Deep Archive (Long-term retention)

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Micro-activity 1: Pick the Storage Class

Micro-activity 2: Lifecycle & Logic

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Summary

Amazon S3 offers a wide range of storage classes to balance cost and performance. By understanding access frequency and retrieval requirements, you can use Storage Classes and Lifecycle Policies to build highly cost-effective cloud storage architectures.

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Knowledge Check

Next lesson

Lesson 4.10: EBS, EFS, and FSx