Storage¶

AWS has three storage families: object (S3), block (EBS), and file (EFS). Understanding which to use — and why — is one of the most common architectural decisions in cloud.

Storage Fundamentals

Block vs object vs file storage, backup strategies (full/incremental/differential), and the disaster stories that explain why backups matter.

Fundamentals
S3

Object storage — bucket policies, access control, storage classes, versioning, lifecycle policies, replication, and encryption.

S3
EBS

Block storage for EC2. Volume types, snapshots, security labs (volume zeroing, snapshot forensics, SSRF chain), and instance store.

EBS

Storage Quick Reference¶

Need to attach a disk to an EC2 instance?
  -> EBS (Block storage)

Need a shared filesystem mounted by multiple EC2s?
  -> EFS (File storage, NFS protocol)

Need to store files, backups, logs, static assets, data lakes?
  -> S3 (Object storage)

Need the absolute fastest storage for a database?
  -> EBS io2 Block Express (high IOPS)

Need temporary storage that's as fast as RAM-like speeds?
  -> EC2 Instance Store (ephemeral -- lost when instance stops)

Need to archive 7 years of compliance data cheaply?
  -> S3 Glacier Deep Archive

Storage Type Comparison¶

Feature	EBS	EFS	S3
Type	Block	File	Object
Access	One EC2 (mostly)	Multiple EC2s	HTTP API
Protocol	iSCSI	NFS	REST
Use case	OS, databases	Shared config, CMS	Backups, media, data lake
Persistence	Survives instance stop	Survives instance stop	Permanent
Region	AZ-specific	Regional	Global