What is Amazon EFS?
Amazon Elastic File System (EFS) provides a simple, serverless, set-and-forget elastic file system. It lets you create a standard file system that can be mounted by multiple EC2 instances at the same time.
Key Concepts
- Protocol: Uses the standard NFSv4 (Network File System) protocol.
- Linux Only: Primarily designed for Linux instances (for Windows, see FSx).
- Shared Access: Hundreds or thousands of EC2 instances can access the file system simultaneously.
- Multi-AZ: Data is stored across multiple Availability Zones for high durability.
Exam Tips
[!IMPORTANT] EBS vs EFS:
- EBS: Block Storage. Attached to ONE instance at a time (mostly). Fast, low latency.
- EFS: File Storage. Attached to MANY instances. Scalable, shared throughput.
[!NOTE] Performance: EFS grows automatically as you add files. You don't need to provision size.
Common Use Cases
- Web Serving: Storing shared content/media assets for a fleet of web servers.
- Home Directories: Storing user home directories across a cluster.