EFS is a shared network drive that MANY EC2 instances can use at the same time.

Think of it like a Google Drive for your EC2 instances — multiple servers can connect to it and all see the same files at the same time.

Can be regional (works across multiple AZs) or single zone — whatever you select when creating it.

Why EFS? The Problem it Solves

Normally, each EC2 instance has its own EBS storage (like its own personal hard drive). If you have 3 web servers, each has its own separate storage. They cannot share files with each other.

This becomes a problem when:

• User uploads a file to Server 1 — Server 2 and Server 3 don't see it
• You update a config file on Server 1 — other servers still have the old version
• Each server has a different version of the same data

EFS solves this by giving all servers one shared storage that they all read from and write to.

EBS vs EFS — Key Difference

EBS = Personal USB stick

Only you can use it
One person at a time

EFS = Shared network folder

Everyone in the office can access it
Multiple people at once
All see the same files

Key Features