The Benefits of Using Amazon EFS for Scalable File Storage

Amazon Elastic File System (EFS) is a managed file storage service that scales automatically as you add or remove files. It works with EC2 instances and lets multiple machines access the same data at once, which makes it useful for a range of workloads. This post covers when EFS makes sense, what you get out of it, and how the costs work.

When Should You Use Amazon EFS?

EFS handles concurrent access from multiple EC2 instances, so it fits workloads where several machines need to read and write the same files. Common examples include web servers, media streaming, content delivery networks, and analytics platforms. It also handles large media files, documents, and other bulky data without breaking a sweat.

Business scenarios where EFS tends to be the right call

Web Applications:

Web apps often run multiple instances behind a load balancer. EFS provides a POSIX-compatible file system that all instances can mount simultaneously, so you get shared storage without extra infrastructure overhead.

Content Management Systems:

CMS platforms like WordPress need a central place for uploads, themes, and plugins. EFS gives you a scalable repository that plays well with containerized deployments.

Big Data Analytics:

Analytics workloads frequently need access to large datasets across many workers. EFS delivers high throughput and low latency, which matters when you’re processing data in real time.

DevOps and CI/CD pipelines:

Build agents and deployment services often need access to shared artifacts. EFS serves as a central repository for code and binaries, making pipeline management simpler.

High-performance computing (HPC):

HPC clusters require fast, shared storage across many nodes. EFS scales to meet the demands of scientific computing workloads without requiring you to manage any hardware.

Machine learning (ML) and artificial intelligence (AI):

Training machine learning models involves large datasets that need to be accessible across training instances. EFS provides the capacity and availability that ML workflows require.

Why Is Amazon EFS Beneficial?

EFS scales up or down automatically based on how much data you store. You provision capacity in minutes, and there’s no downtime or service interruption while it happens. The service replicates data across multiple Availability Zones, which protects you against outages. Since AWS manages the underlying infrastructure, you skip the hardware and software maintenance work.

Lifecycle management

EFS Intelligent-Tiering automatically moves files you haven’t accessed in 30 days to Standard-Infrequent Access (IA) storage. The lifecycle policy monitors access patterns and handles the transition for you. Files in IA cost less, and you don’t have to manually move them or rebuild your application to take advantage.

Throughput mode

EFS offers three throughput modes: Bursting, Provisioned, and Elastic.

Bursting mode scales throughput with your storage capacity. If you store more data, you get more burst credits. This works well for applications with baseline performance needs, like backup or archival workloads.

Provisioned mode lets you set a specific throughput level independently of storage size. This is useful when you need consistent performance and know your requirements ahead of time.

Elastic mode automatically adjusts throughput based on your workload. AWS handles the scaling, which saves you from guessing capacity upfront. This mode suits unpredictable or highly variable workloads.

Backup

AWS Backup handles EFS file system backups automatically. You choose a schedule (daily, weekly, or monthly) and set retention periods. AWS manages backup lifecycles and stores reports about backup status and contents. Deleted files and accidental overwrites are protected within your retention policy.

Encryption

EFS encrypts data at rest using AES-256 or equivalent. You enable encryption when creating the file system, and AWS manages the keys through AWS Key Management Service (KMS). For data in transit, EFS uses TLS 1.2 to encrypt NFS mounts. If you need FIPS-compliant endpoints for regulated workloads, those are available through AWS GovCloud regions.

AWS Services Supported

EFS integrates with several AWS services. ECS and Fargate can mount EFS volumes for containerized workloads, which works well for microservices that need shared storage. Lambda functions can access EFS through VPC endpoints, enabling serverless applications to read and write shared data without managing their own storage. SageMaker uses EFS for training data, making it straightforward to feed large datasets into ML models.

EFS also works with VPC endpoints, so you can access your file system privately without routing traffic over the internet.

Configurations

Security Group

To connect an EC2 instance to an EFS file system, the security group attached to your mount target needs two inbound rules:

1. Allow TCP port 2049 (NFS) from the EC2 instance’s security group
2. Allow TCP port 2049 from any IP address if needed for testing

The EC2 instance’s security group also needs inbound rules:

• For IPv4: allow TCP ports 2049 and 111 from any address
• For IPv6: allow TCP ports 2049 and 111 from the mount target’s security group

Once your security groups are configured correctly, mounting the file system is straightforward.

What Are the Cost Impacts of Using Amazon EFS?

EFS pricing is based on storage consumed, not provisioned capacity. As of 2025, Standard storage runs about $0.30 per GB-month, and Standard-IA runs about $0.025 per GB-month. There’s no upfront fee and no minimum commitment. You pay only for what you use.

For context, storing 10GB in Standard tier costs roughly $3 per month. The same data in S3 costs around $0.23 per month, but S3 doesn’t support concurrent mounts from multiple instances the way EFS does. If your workload needs shared access, EFS is the more practical choice despite the higher per-GB cost.

Data transfer and API requests add to your bill when you move data between regions or out of AWS.

Limitations

Cost: EFS costs more per GB than S3 or EBS, especially for workloads with heavy access patterns. If cost is the primary concern, evaluate whether your data access fits S3’s model instead.

Operating System: EFS only supports Linux-based EC2 instances. Windows is not supported.

Locking: Each mount target supports up to 65,536 locks per connection. Directory operations don’t count toward this limit.

Open files: A single instance can have up to 32,768 open files on an EFS file system.

Maximum file size: Individual files can be up to 47.9 TiB, which covers most use cases.

Conclusion

EFS isn’t the cheapest storage option on AWS, but it handles concurrent access, automatic scaling, and cross Availability Zone redundancy in ways that simpler solutions can’t. If you need shared file storage across multiple Linux instances without managing your own infrastructure, EFS does the job. For workloads that fit its model, the convenience and reliability are worth the premium over commodity object storage.