EFS (Elastic File System)
💡 Definition
Amazon EFS provides simple, scalable, elastic file storage for use with AWS cloud services and on-premises resources. It is designed to be highly available and durable, and can be accessed concurrently by thousands of EC2 instances.
🔑 Key Concepts
- File Storage: Provides network file system (NFS) storage that can be shared across multiple instances.
- Scalable: Automatically scales file system storage up or down as you add or remove files.
- Elastic: You only pay for the storage you use; no need to provision storage in advance.
- Shared Access: Multiple EC2 instances (even across different AZs) can access the same EFS file system simultaneously.
⚙️ How it Works
- Create File System: You create an EFS file system.
- Mount Targets: Create mount targets in your VPC's Subnets (one per AZ).
- Mount on EC2: Mount the EFS file system onto your EC2 instances using the NFS protocol.
🎯 Use Cases
- Content Management Systems: Storing shared media files, user-generated content.
- Web Serving: Centralized storage for web application data.
- Development & Test Environments: Shared code repositories and build artifacts.
- Big Data Analytics: Storing large datasets that need to be accessed by many compute instances.
💰 Pricing Model
- Storage: Pay for the amount of storage consumed per month. No charges for provisioned capacity.
📝 Exam Tips (CLF-C02)
- EFS is a Network File System (NFS).
- It provides shared access for multiple EC2 instances.
- Automatically scales storage capacity.
- Contrasted with EBS (single instance block storage) and S3 (object storage).