Amazon Elastic File System
Overview
Amazon EFS is highly durable network file system as a service to EC2 instances. It supports NFSv4 and NFSv4.1 which helps migrate enterprise applications to AWS or build new ones easily. No need to provision storage in advance since EFS is designed to grow to petabytes, which allows massive parallel access from EC2 instances to your data within a Region. File system can be accessed via mount targets that are created per Availability Zone. Only one mount target can be created per Availability Zone in the VPC. Traffic between EFS and EC2 is controlled through security groups associated with the EC2 instance and the EFS mount targets. standard Unix-style read/write/execute permissions are used for EFS file system objects access control based on user and group IDs.
Usage Patterns
- Concurrent access data from multiple EC2 instances
- High levels of aggregate throughput and IOPS
- Small latency overhead for each file operation
- Ideal for growing datasets consisting of larger files that need hight performance and multi-client access
- Well suited for big data and analytics, media processing, content management, web serving, and home directories
Storage Needs for which you should consider other AWS storage options
Performance
- Massive parallel access within a Region
- Performance modes: General Purpose (file operations under 7,000)and Max I/O(file operations over 7,000, with some tradeoff of higher latencies for file operations)
- Optimized to burst at spikes but a credit system determines when an EFS file system can burst(BurstCreditBalance metric can be found in CloudWatch)
- Newly created file systems start with a credit balance of 2.1 TiB with a baseline rate of 50 MiB/s per TiB of storage and a burst rate of 100 MiB/s.
- Bursting behaviors for file systems of different sizes.
- Asynchronous writes with tradeoff of speed consistency
Durability and Availability
- EFS files system object such as a directory, file, or link is redundantly stored across multi AZ within a Region
- Durable and available as Amazon S3
Scalability and Elasticity
- Can grow from an empty file system to multiple petabytes automatically
- No provisioning, allocating, or administration
Security
- 3 levels of access control: 1) IAM permissions for API calls, 2) Security groups for Ec2 instances and mount targets, 3) Network File System-level users, groups, and permissions
- IAM Identity( IAM user or IAM role) to create, delete, and describe EFS file system resources
- Primary resource is a file system
- Subresources are mount targets and tags
- Users and groups are mapped to numeric identifiers that are mapped to EFS users to represent file ownership
Interfaces
- offers a network protocol-based HTTP API for managing Amazon EFS
- Support for EFS operations within the AWS SDKs and the AWS CLI
Cost Model
- Pay for the amount of storage you put into the file system
- No charges for bandwidth or requests
- No minimum commitments or up-front fees
