BeginnerStorage

Storage Services

Learn S3 object storage, EBS block storage, and EFS file storage, and how each maps to Azure storage options.

What Is It? (ELI5)

S3 is a giant cloud cupboard for files, EBS is a hard disk attached to a VM, and EFS is a shared network drive for multiple servers.

Why Do We Need It?

Different workloads need different storage behavior.
Apps need durable, scalable, and cost-aware storage choices.
Architecture decisions affect performance and recovery speed.

How It Works (Technical)

AWS	Type	Best For	Azure Equivalent
S3	Object	Images, backups, logs, static websites	Blob Storage
EBS	Block	OS disks and low-latency app data	Managed Disks
EFS	File	Shared POSIX file system across EC2	Azure Files

Visual Representation

App uploads images -> S3 bucket
EC2 boot disk -> EBS volume
Multiple EC2 instances -> EFS mount target

Hands-on

# Create and use S3 bucket
aws s3 mb s3://my-skilly-demo-bucket
aws s3 cp app.log s3://my-skilly-demo-bucket/logs/app.log

# Create EBS volume (example)
aws ec2 create-volume --availability-zone us-east-1a --size 20 --volume-type gp3

Debugging Scenario

Problem

File upload to S3 fails with AccessDenied.

Check IAM policy allows s3:PutObject on target bucket path.
Review bucket policy for explicit deny.
Confirm KMS key permissions if encryption is enforced.

Interview Questions

Beginner: S3 vs EBS?
S3 is object storage over API; EBS is block storage attached to EC2.

Intermediate: When choose EFS?
When many EC2 instances need shared file access simultaneously.

Scenario: Your web app needs globally distributed static content.
Use S3 with CloudFront CDN to reduce latency worldwide.

Real-world Usage

Media platforms store uploads in S3, metadata in database, and use lifecycle rules to move older objects to cheaper classes.

Summary

S3 for objects, EBS for VM disks, EFS for shared file workloads.
Pick storage by access pattern, latency, and sharing needs.
IAM and encryption setup are common operational blockers.