Amazon Elastic File System
Amazon EFS provides a simple, scalable, fully managed elastic NFS file system for use with AWS Cloud services and on-premises resources. It is designed to grow and shrink automatically as you add and remove files.
A fully managed, scalable, and elastic NFS file system for AWS.
Amazon EFS is a cloud-native file storage service that follows the Network File System (NFS) protocol. Unlike EBS (which attaches to a single EC2 instance), EFS can be mounted concurrently by thousands of EC2 instances across multiple availability zones. Think of it as a shared network drive that multiple servers can access at the same time.
EFS automatically scales its storage capacity — you don't need to provision storage in advance. As you add files, EFS grows. As you delete files, EFS shrinks. You pay only for the storage you use, with no minimum commitments.
Understanding the differences between AWS storage options.
| Feature | EFS | EBS | S3 |
|---|---|---|---|
| Type | File Storage (NFS) | Block Storage | Object Storage |
| Access | Multiple EC2 instances | Single EC2 instance | Via internet / SDK |
| Scaling | Auto-scaling (no provisioning) | Manual provisioning | Auto-scaling |
| Use Case | Shared files, web serving | OS, databases | Backups, media, data lakes |
| Protocol | NFS v4.1 | Block-level | REST API |
| Persistence | Persistent, shared | Persistent, single-attach | Persistent, global |
EFS is deployed across multiple Availability Zones for high availability.
EC2 Instances
Multiple instances across Availability Zones
Mount Targets
One mount target per Availability Zone
EFS File System
POSIX-compliant, auto-scales with usage
S3 (Lifecycle)
EFS IA tier auto-moves cold data
You create a mount target in each Availability Zone where you want to access the file system. EC2 instances in those AZs mount the file system using the standard NFS mount command. EFS automatically replicates data across AZs within a region for durability up to 99.999999999% (11 9's).
What makes EFS the right choice for shared file workloads.
Grows and shrinks automatically. No need to provision storage — just create the file system and start using it.
Standard storage class is regional (multi-AZ) with 11 9's durability. One Zone is for lower-cost, single-AZ workloads.
Choose General Purpose (low latency) or Max I/O (high throughput, parallel workloads). Bursting or Provisioned throughput.
EFS supports standard POSIX permissions (chmod, chown), file locking, and user/group IDs — just like a local file system.
Automatically move infrequently accessed files to EFS Infrequent Access (IA) to reduce costs by up to 92%.
Connect on-premises servers to EFS using AWS Direct Connect or VPN. Your local applications can share files with cloud apps.
How EFS powers shared file workloads at scale.
Research institutions use EFS to share genomic datasets across hundreds of EC2 instances for high-performance computing.