EFS full guide

What Is Amazon EFS?

Amazon EFS (Elastic File System) is a scalable, cloud-based file system that can be shared between multiple EC2 instances — just like a shared network drive.

It’s perfect for:

• Web applications that need shared storage


• CI/CD pipelines


• Clusters or load-balanced servers

Unlike EBS, which attaches to one EC2 instance only, EFS can be accessed by many EC2s at the same time.

🚀 Step 1: Create an EFS File System

1. In the AWS Console, search for EFS (Elastic File System).


2. Click Create file system.


3. Enter:

• 
  Name: efs-demo
  


• 
  VPC: Choose your default VPC (for example vpc-0f5cbbc2f3ce5786b)
  
  
  
  
  1. Keep the default settings (Regional, automatic mount targets).
  
  
  2. Click Create.
  
  
  
  

💡 Result:

This creates your EFS file system and 3 mount targets — one in each Availability Zone (us-east-2a, us-east-2b, us-east-2c).

These targets are how EC2 connects to your EFS.

🧩 Step 2: Configure Network Access

2.1 Find EFS Security Group

• Go to EFS → File systems → Your EFS (fs-xxxxxxxx)
  


• Click the Network tab.


• Copy the Security Group ID (for example, sg-0fcb6a7e70b6fa5e3).

2.2 Allow EC2 to Access EFS

Now we’ll let your EC2 security group communicate with EFS.

1. Go to VPC → Security Groups.


2. Search for your EFS group:
   

   sg-0fcb6a7e70b6fa5e3

1. Click on it → Inbound Rules → Edit inbound rules → Add rule.
   

Add:

1. Click Save rules.

💡 Result:

This allows traffic between your EC2 and EFS over port 2049 (NFS).

💻 Step 3: Launch an EC2 Instance

1. Go to EC2 → Launch instance.
   


2. Choose:

• 
  Name: efs-demo
  


• 
  AMI: Ubuntu 24.04 or Amazon Linux 2


• 
  Instance type: t3.micro
  


• 
  Network: same VPC as EFS (vpc-0f5cbbc2f3ce5786b)


• 
  Subnet: same Availability Zone as your EFS mount target (e.g., us-east-2c)


• 
  Security group: choose the one you used in the EFS rule (sg-0114625bd0ada61c9)
  
  
  
  
  1. Click Launch instance.
     
  
  
  
  

🧠 Step 4: Connect to EC2 (Using the AWS Console)

1. Go to EC2 → Instances.


2. Select your instance (efs-demo).


3. Click the Connect button at the top.


4. Choose EC2 Instance Connect tab.


5. Click Connect again.

✅ You will now see a Linux terminal in your browser:

ubuntu@ip-172-31-47-6:~$

That’s your EC2 command line — you don’t need any SSH key or setup!

⚙️ Step 5: Check Your Availability Zone

Run:

curl http://169.254.169.254/latest/meta-data/placement/availability-zone

✅ Expected output:

us-east-2c

💡 This confirms which Availability Zone your EC2 is in — it must match one of your EFS mount targets.

🛠 Step 6: Install Amazon EFS Utilities

sudo apt update

sudo apt install -y git binutils make pkg-config

git clone https://github.com/aws/efs-utils

cd efs-utils

sudo ./build-deb.sh

sudo apt install -y ./build/amazon-efs-utils*deb

✅ Purpose:

The EFS Utilities package allows you to use mount -t efs instead of manually configuring NFS.

📂 Step 7: Create a Mount Directory

sudo mkdir -p /mnt/efs/efs

💡 This is where your EFS will appear, like a shared folder on your local drive.

🔗 Step 8: Mount the EFS

Now mount your EFS file system to the directory you created.

sudo mount -t efs -o tls fs-0ab10783d27483a12:/ /mnt/efs/efs

✅ Explanation:

• 
  -t efs → tells Linux to use the EFS driver


• 
  -o tls → enables encryption


• 
  fs-0ab10783d27483a12 → your EFS ID


• 
  /mnt/efs/efs → the directory on your EC2

🧾 Step 9: Verify the Mount

df -hT

✅ Example output:

Filesystem                              Type  Size  Used Avail Use% Mounted on

fs-0ab10783d27483a12.efs.us-east-2.amazonaws.com:/  efs  8.0E   0  8.0E   0%  /mnt/efs/efs

🎯 This confirms your EFS is successfully mounted.

🧪 Step 10: Test Write Access

sudo touch /mnt/efs/efs/test.txt

ls -l /mnt/efs/efs

✅ Example result:

-rw-r--r-- 1 root root 0 Oct 9 04:10 test.txt

🎉 You just created a file on your EFS — if another EC2 instance mounts the same EFS, it will see the same file instantly.

🔁 Step 11: Auto-Mount on Reboot

Make EFS mount automatically every time your instance restarts.

1. Edit /etc/fstab:
   

   sudo nano /etc/fstab

1. Add this line:
   

   fs-0ab10783d27483a12:/ /mnt/efs/efs efs _netdev,tls 0 0

1. Save (Ctrl + O, then Enter, then Ctrl + X)




2. Test:
   
   

   sudo mount -a

   df -hT

✅ Purpose:

Ensures your EFS mounts automatically on reboot without manual intervention.

🧭 Step 12: Confirm in the Console

EFS does not show up as “attached” under EC2 → Storage like EBS.

Instead:

• Go to EFS → File systems → fs-0ab10783d27483a12 → Monitoring
  


• Under “Client connections,” you’ll see your EC2 listed as connected.

✅ This confirms your EC2 instance is actively using the EFS.

🏁 Final Summary