What is Amazon Elastic File System? - Amazon Elastic File System
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What is Amazon Elastic File System?

Amazon Elastic File System (Amazon EFS) provides serverless, fully elastic file storage so that you can share file data without provisioning or managing storage capacity and performance. Amazon EFS is built to scale on demand to petabytes without disrupting applications, growing and shrinking automatically as you add and remove files. Because Amazon EFS has a simple web services interface, you can create and configure file systems quickly and easily. The service manages all the file storage infrastructure for you, meaning that you can avoid the complexity of deploying, patching, and maintaining complex file system configurations.

Amazon EFS supports the Network File System version 4 (NFSv4.1 and NFSv4.0) protocol, so the applications and tools that you use today work seamlessly with Amazon EFS. Multiple compute instances, including Amazon EC2, Amazon ECS, and Amazon Lambda, can access an Amazon EFS file system at the same time. Therefore, an EFS file system can provide a common data source for workloads and applications that are running on more than one compute instance or server.

With Amazon EFS, you pay only for the storage used by your file system and there is no minimum fee or setup cost. Amazon EFS offers a range of storage classes designed for different use cases. These include:

  • Standard storage classes – EFS Standard and EFS Standard–Infrequent Access (Standard–IA), which offer Multi-AZ resilience and the highest levels of durability and availability.

  • One Zone storage classes – EFS One Zone and EFS One Zone–Infrequent Access (EFS One Zone–IA), which offer you the choice of additional savings by choosing to save your data in a single Availability Zone.

For more information, see EFS storage classes. Costs related to Provisioned Throughput are determined by the throughput values that you specify. For more information, see Amazon EFS Pricing.

Amazon EFS is designed to provide the throughput, IOPS, and low latency needed for a broad range of workloads. With Amazon EFS, you can choose from two performance modes and three throughput modes:

  • The default General Purpose performance mode is the recommended mode. General Purpose is ideal for latency-sensitive use cases, like web-serving environments, content-management systems, home directories, and general file serving.

  • File systems in the Max I/O performance mode can scale to higher levels of aggregate throughput and operations per second. However, these file systems have higher latencies for file system operations. For more information, see Performance modes.

  • With the default Bursting Throughput mode, throughput scales with the amount of storage in your file system and supports bursting to higher levels for up to 12 hours per day.

  • With Elastic Throughput mode, Amazon EFS automatically scales throughput performance up or down to meet the needs of your workload activity.

  • With Provisioned Throughput mode, you specify a level of throughput that the file system can drive independent of the file system's size or burst credit balance. For more information, see Throughput modes.

The service is designed to be highly scalable, highly available, and highly durable. Amazon EFS file systems using Standard storage classes store data and metadata across multiple Availability Zones in an Amazon Web Services Region. EFS file systems can grow to petabyte scale, drive high levels of throughput, and allow massively parallel access from compute instances to your data.

Amazon EFS provides file-system-access semantics, such as strong data consistency and file locking. For more information, see Data consistency in Amazon EFS. Amazon EFS also supports controlling access to your file systems through Portable Operating System Interface (POSIX) permissions. For more information, see Security in Amazon EFS.

Amazon EFS supports authentication, authorization, and encryption capabilities to help you meet your security and compliance requirements. Amazon EFS supports two forms of encryption for file systems: encryption in transit and encryption at rest. You can enable encryption at rest when creating an Amazon EFS file system. If you do, all your data and metadata is encrypted. You can enable encryption in transit when you mount the file system. NFS client access to EFS is controlled by both Amazon Identity and Access Management (IAM) policies and network security policies, such as security groups. For more information, see Data encryption in Amazon EFS, Identity and access management for Amazon EFS, and Controlling network access to Amazon EFS file systems for NFS clients.


Using Amazon EFS with Microsoft Windows–based Amazon EC2 instances is not supported.

Are you a first-time user of Amazon EFS?

If you are a first-time user of Amazon EFS, we recommend that you read the following sections in order:

  1. For an Amazon EFS product and pricing overview, see Amazon EFS.

  2. For an Amazon EFS technical overview, see Amazon EFS: How it works.

  3. Try the introductory exercises:

If you want to learn more about Amazon EFS, the following topics discuss the service in greater detail: