AWS EFS for Beginners: The Complete Guide to Amazon Elastic File System
In today's cloud-driven world, applications often need shared access to files across multiple servers. While Amazon S3 and EBS are great for specific storage use cases, Amazon EFS (Elastic File System) is built for one specific job: providing a shared, scalable file system that can be used across multiple Amazon EC2 instances.
If you're just getting started with AWS and wondering when and why to use EFS, this beginner-friendly guide covers everything you need to know — including key concepts, use cases, pricing, and step-by-step deployment advice.
What is AWS EFS?
Amazon Elastic File System (EFS) is a fully managed, scalable file storage service that lets you share data across multiple EC2 instances using the NFS (Network File System) protocol.
Unlike EBS, which is tied to a single instance, or S3, which uses object storage, EFS is designed like a traditional file system — supporting directories, permissions, and simultaneous access from multiple instances.
How EFS Works
At a high level:
You create a file system in EFS.
It is mounted to one or more EC2 instances via NFS.
Any instance can read/write to it in real time.
Files are stored redundantly across multiple Availability Zones (AZs).
EFS automatically scales capacity as you add/remove files.
EFS vs EBS vs S3: Key Differences
| Feature | EFS | EBS | S3 |
|---|---|---|---|
| Type | File System | Block Storage | Object Storage |
| Access | Multiple EC2s (shared) | Single EC2 (attached) | Public/Private via API |
| Best Use Case | Shared access, CMS, logs | Databases, boot volumes | Media storage, backups |
| Mountable | Yes (NFS) | Yes (as disk) | No (access via URL/API) |
| Pricing Model | Per GB/month + throughput | Per GB/month | Per GB + request count |
Common Use Cases for Amazon EFS
Web hosting — Store WordPress media uploads, configuration files
Big data processing — Analytics platforms that require simultaneous access to data
Machine learning — Shared datasets across training jobs
DevOps — Central logging for multiple EC2 instances
Lift-and-shift — Migrate on-premises applications that expect a standard file system
Key Features of EFS
Elastic Storage
EFS automatically scales from MBs to petabytes as files are added or removed.
Shared Access
Multiple EC2 instances across Availability Zones can access the file system simultaneously.
POSIX Compliance
Supports standard Linux file permissions, symbolic links, hard links, etc.
Managed Backups
EFS integrates with AWS Backup for scheduled or on-demand file backups.
Durability & Availability
EFS stores data redundantly across multiple AZs, ensuring high availability.
How to Set Up AWS EFS (Step-by-Step)
Here’s a simplified setup guide for beginners:
Step 1: Create an EFS File System
Go to AWS Console > EFS
Click “Create file system”
Choose VPC, configure mount targets across multiple AZs
Step 2: Launch EC2 Instance(s)
Make sure your instances are in the same VPC and security group as the EFS file system.
Step 3: Install NFS Utilities (Linux)
SSH into your instance:
Step 4: Mount the File System
Use the DNS name provided by AWS:
Now, any files written to /mnt/efs are shared across all instances mounting this EFS.
AWS EFS Pricing Overview
EFS offers two storage classes:
| Storage Class | Description | Price (approx) |
|---|---|---|
| Standard | Frequent access, high performance | ~$0.30/GB/month |
| Infrequent Access (IA) | Cost-saving for rarely accessed data | ~$0.025/GB/month |
You also pay for:
Throughput provisioned (or auto mode)
Data transfer between AZs
Example:
100 GB in Standard storage ≈ $30/month
100 GB in IA storage ≈ $2.50/month
Security Features in EFS
Encryption at rest and in transit using AWS KMS
IAM access control for file system management
VPC security groups to restrict mount access
AWS Backup integration for secure snapshots
Audit logging with CloudTrail
EFS is also HIPAA, GDPR, SOC, and PCI compliant, making it a solid choice for enterprise workloads.
Tips and Best Practices for Beginners
Use Access Points to simplify permissions and multi-tenant file access
Enable Lifecycle Management to move unused files to IA and save cost
Automate mount at instance startup using
/etc/fstab
Monitor performance with Amazon CloudWatch
Pair EFS with AWS Lambda for serverless file processing at scale
Final Thoughts: Why Learn AWS EFS?
If you're working with applications that need a shared, secure, and scalable file system, Amazon EFS is the perfect AWS solution. It bridges the gap between local file systems and cloud-native scalability, offering the best of both worlds.
Whether you’re building a cloud-native app, migrating a legacy system, or deploying a CMS on EC2, EFS helps you manage file storage easily without worrying about capacity planning, redundancy, or scaling.