Amazon EFS
A shared network folder in AWS that many servers can use at the same time.
Amazon EFS (Elastic File System) is a managed file system that lives on the network. You create one, and then several servers can mount it at once and see the same folders and files, as if they all had the same drive plugged in. It speaks NFS, the standard protocol Linux machines use to share files.
Compare it with its neighbors. An EBS volume is like a hard disk attached to one EC2 instance. Amazon S3 stores objects that you read and write through an API, not a folder you can open with normal programs. EFS sits in between: a real file system with directories and permissions, shared by many EC2 instances, containers on ECS or EKS, and even Lambda functions.
Typical uses are content that several web servers must share, like images uploaded by users, home directories for a team, or data that a group of machines processes together. It grows and shrinks on its own as you add or delete files, and you pay for what you store. Files can move automatically to cheaper storage classes when nobody touches them for a while. It is for Linux; Windows file shares use a different service, Amazon FSx.
Keep in mind
- A network file system many servers can mount at the same time.
- Uses NFS and works with Linux EC2, ECS, EKS and Lambda.
- Grows automatically; you pay for the storage you actually use.
- EBS is one disk for one server; S3 is objects through an API; EFS is a shared folder.
