Amazon Elastic File System (EFS) Hands-On Guide

In this hands-on session, we explored Amazon Elastic File System (EFS) and how to create, configure, and mount it to EC2 instances. Below is a structured guide summarizing all the steps.

1. Creating an EFS File System

1. Navigate to the EFS Console
   • Click on Create file system.
   • (Optional) Provide a name or leave it blank.
   • Choose a VPC (default is fine).
2. Customize File System Settings
   • File System Type:
     • Regional (Recommended for production) – Spans multiple Availability Zones (AZs) for high durability.
     • One Zone (Cost-effective) – Restricted to a single AZ (not recommended for production).
   • Automatic Backups: Keep enabled for data protection.
   • Lifecycle Management: Saves costs by transitioning data across storage tiers:
     • 30 days inactive → Moves to Infrequent Access.
     • 90 days inactive → Moves to Archive.
     • Accessed again → Moves back to Standard.
   • Encryption: Keep enabled (best practice).
   • Performance Settings:
     • Bursting Throughput Mode – Scales based on storage size.
     • Elastic Throughput Mode (Recommended) – Provides dynamic throughput without pre-configured limits.
     • Provisioned Throughput Mode – Best when throughput needs are known in advance.
   • Performance Mode:
     • General Purpose (Recommended) – Low latency, good for most applications.
     • Max I/O – Suitable for high-throughput workloads but with increased latency.
3. Network Access Configuration
   • Choose a VPC (default VPC is fine).
   • EFS will automatically create mount targets for each AZ.
   • Assign a security group (create a new one for EFS if needed).
4. Review and Create
   • Ensure settings are correct, then Create the EFS file system.

2. Attaching EFS to EC2 Instances

Step 1: Launch EC2 Instance A

1. Navigate to the EC2 Console and click Launch Instance.
2. Configure the instance:
   • Name: Instance A.
   • AMI: Amazon Linux 2.
   • Instance Type: t2.micro (Free-tier eligible).
   • Key Pair: No key pair (use EC2 Instance Connect for SSH).
   • Network Settings: Default VPC, select subnet in eu-west-1a.
   • Security Group: Create a new one or use an existing EFS security group.
3. Attach EFS Storage:
   • Under "Advanced details" → Add an EFS file system.
   • Mount path: /mnt/efs/fs1/.
   • AWS automatically mounts the EFS using user data scripts.
4. Launch the instance.

Step 2: Launch EC2 Instance B

• Repeat the above steps, but:
  • Name it Instance B.
  • Place it in eu-west-1b.
  • Select the same EFS file system.

3. Testing EFS File Sharing

1. Connect to Instance A:

   ls /mnt/efs/fs1/
   sudo su
   echo "hello world" > /mnt/efs/fs1/hello.txt
   cat /mnt/efs/fs1/hello.txt
   
   

   • Creates hello.txt in EFS.