AWS Storage Services: EBS, Instance Store, EFS

EBS (Elastic Block Store)

Network-attached virtual hard drive for a single EC2 instance at a time.

EBS Availability Zone Boundary

Volumes are AZ-locked; moving to another AZ requires creating and restoring a Snapshot.

EBS Billing Model

Charged for provisioned size and performance, regardless of actual usage.

EBS gp3

Default SSD volume allowing performance (IOPS) scaling independently of storage capacity.

EBS io1 / io2

High-performance SSD for databases >16,000 IOPS; supports Multi-Attach.

EBS st1 (Throughput HDD)

Low-cost throughput-optimized HDD for Big Data/logs; cannot be an OS boot volume.

EBS sc1 (Cold HDD)

Cheapest HDD storage for infrequently accessed data; cannot be an OS boot volume.

EBS Snapshots

Incremental backups of EBS volumes stored silently in Amazon S3.

Steps to Encrypt an Unencrypted EBS Volume

Take Snapshot $\rightarrow$ Copy snapshot with encryption enabled $\rightarrow$ Restore new volume.

Amazon Machine Image (AMI)

Regional blueprint of a configured EC2 instance backed by EBS snapshots.

EC2 Instance Store

Physically attached local SSD providing ultra-low latency, maximum speed ephemeral storage.

EC2 Instance Store Data Retention

Data is permanently lost when Stopped or failed; survives only basic OS reboots.

Amazon EFS (Elastic File System)

Managed NFS file system shared concurrently across Linux instances in multiple AZs.

Amazon EFS Compatibility & Billing

Linux-only service; automatically scales so you pay only for storage used.

Storage Monthly Hosting Cost Order (Lowest to Highest)

Amazon S3 Standard < Amazon EFS < Amazon EBS