Amazon EFS: Scalable File Storage

• Amazon Elastic File System (Amazon EFS) is a scalable, fully managed file storage service for AWS cloud services and on-premises resources.
• It offers a simple, scalable, highly available file system that can be mounted to multiple Amazon EC2 instances or on-premises servers simultaneously for data sharing.

What is Amazon EFS?

• Amazon EFS is a cloud-based file storage system designed for workloads needing a common file system shared across multiple instances or servers.
• It provides a simple interface for creating and configuring file systems and automatically scales storage capacity as data grows, without manual intervention.
• It is ideal for applications needing shared access to data, like content management systems, web serving, big data analytics, media workflows, and home directories.

Key Features of EFS

• EFS is a fully managed service, meaning AWS handles infrastructure management, including provisioning, patching, scaling, and redundancy.
• EFS automatically scales its capacity as data is added or removed, without manual resizing, and users pay only for the storage they use.
• EFS automatically scales performance to meet workload needs, ensuring low latency and high throughput.
• EFS is designed to be highly available, with data replicated across multiple availability zones (AZs) within a region for data resilience.
• The same file system can be mounted on multiple EC2 instances simultaneously, enabling shared data access, and EFS supports NFSv4, a standard file protocol for Unix-like systems.
• Unlike temporary storage on EC2 instances, EFS offers persistent storage that remains available even if EC2 instances are terminated or restarted.
• EFS integrates with AWS Identity and Access Management (IAM) and Amazon Virtual Private Cloud (VPC) to provide network security and access control, including encryption at rest and in transit.

How Amazon EFS Works

• Amazon EFS uses the Network File System (NFS) protocol to allow EC2 instances to access data stored in the file system.
• When an EC2 instance mounts the EFS file system, it can read and write as if it were a local file system.
• An EFS file system is created in an AWS account.
• The file system is mounted to one or more EC2 instances using the NFS protocol.
• Data stored in the file system is replicated across multiple availability zones (AZs) in the region for fault tolerance.
• As the data grows or shrinks, EFS automatically adjusts storage capacity without intervention.

Storage Classes

• EFS offers two storage classes: Standard and Infrequent Access (IA).
• The Standard storage class is the default and is intended for frequently accessed data, providing low latency and high throughput performance.
• The Infrequent Access (IA) storage class is designed for less frequently accessed files, providing lower storage costs.
• EFS automatically moves data between Standard and IA based on access patterns, optimizing costs.

Use Cases for EFS

• EFS can store web server data, user-generated content, and documents for sharing between multiple web servers for Web Serving & Content Management.
• EFS is suited for analytics or scientific computations requiring large shared storage with multiple instances accessing data concurrently for Big Data Analytics.
• EFS can provide shared file storage for users in large organizations, providing a central location for storing and accessing files for Home Directories.
• Video and audio files can be stored and processed using EFS, allowing systems to access media files for encoding, transcoding, or editing for Media Processing.

EFS Performance

• EFS throughput is scalable, so as storage grows, throughput scales as well, dependent on the amount of data stored in the system.
• EFS supports burst performance for workloads needing temporary throughput bursts, achieving high throughput with minimal latency.
• EFS allows provisioning a fixed throughput, useful for applications with consistent throughput needs.

Data Security in EFS

• EFS supports encryption of data at rest, ensuring files are secure when stored on disk.
• EFS supports encryption of data in transit, so data is encrypted as it travels between EC2 instances and the file system.
• EFS integrates with AWS IAM to control access to the file system, so granular access controls can be defined for users or instances.

EFS Pricing

• EFS pricing is based on the amount of data stored and the chosen storage class.
• Storage Cost is based the storage used (per GB).
• Provisioned Throughput Cost incurs additional costs if chosen.
• Data transfer between EFS and other AWS services in the same region is free, but transfers to different regions or the internet incur charges.

EFS vs. Other AWS Storage Services

• Amazon EBS (Elastic Block Store) is block-level storage typically used for individual EC2 instances and doesn’t offer the same scalability or shared access as EFS.
• Amazon S3 (Simple Storage Service) is object storage providing durable, scalable storage but is not designed for file-based workloads (e.g., NFS access).
• Amazon FSx offers fully managed file systems like Windows File Server and Lustre, optimized for specific workloads like high-performance computing or Windows-based applications.

Benefits of Using EFS

• Simplified management with no capacity planning, patching, or performance tuning needed.
• Grows and shrinks automatically based on the data stored, making it scalable.
• Ensures data is available and replicated across multiple availability zones, making it highly available.
• Offers performance efficiency with low-latency, high-throughput storage.
• Cost-effective because users pay for only the storage used, with options to lower costs using the IA storage class.

General Purpose Performance Mode

• The General Purpose performance mode is the default mode for EFS optimized for latency-sensitive applications, like web servers, content management systems, and small to medium-sized workloads.
• It offers low-latency data access, making it suitable for interactive applications where response time is important.
• It provides automatic throughput scaling as the data stored in the file system increases, proportional to the amount of data stored, and automatically adjusted based on the workload.
• Applications include web hosting, home directories, and content management systems (CMS) requiring low latency and predictable performance.
• This mode can scale from small to large amounts of throughput as data grows, but throughput is tied to the size of the file system.

Max I/O Performance Mode

• The Max I/O performance mode is designed for applications needing high levels of throughput and can tolerate higher latencies.
• It provides significantly higher throughput, useful for big data analytics, machine learning, media processing, and similar workloads handling large amounts of data.
• Latency might be higher than in General Purpose mode; this trade-off is acceptable for applications that can handle higher latencies in favor of massive throughput.
• Ideal use cases are large-scale data analytics, video rendering, scientific simulations, and applications processing large amounts of data concurrently and can tolerate higher latencies.
• Max I/O mode scales across a larger number of EC2 instances and larger amounts of data, providing massive parallelism in throughput.

Throughput Modes (Bursting and Provisioned Throughput)

• Throughput modes specifically control how the system handles throughput and burst performance.
• General purpose workloads are supported where occasional throughput bursts is needed without consistent high-performance requirements.
• Applications needing consistent high throughput are supported, such as large-scale database workloads, video editing, or high-performance computing (HPC) applications.

Bursting Throughput

• In Bursting Throughput mode, the EFS file system automatically provides baseline throughput for the data stored, with the ability to burst higher throughput based on recent usage patterns.
• If the file system is underutilized (e.g., storage capacity is low), it can "burst" to higher throughput levels for short periods, making it ideal for workloads with unpredictable traffic patterns.

Provisioned Throughput

• With Provisioned Throughput mode, users can manually provision the throughput capacity they need, regardless of the amount of data stored.
• This mode is beneficial for workloads with specific, high-throughput requirements exceeding what can be achieved in the Bursting mode; throughput is specified in megabytes per second (MB/s).
• EFS ensures the file system meets that provisioned throughput level, independent of how much data is stored in the system

Performance Characteristics of EFS

• Throughput automatically scales as data grows and is tied to the size of the file system (in GiB).
• In Bursting Throughput mode, the system can burst higher throughput based on usage, while in Provisioned Throughput mode, a fixed throughput is set regardless of data size.
• Latency in General Purpose mode is usually low, while Max I/O mode can handle larger throughput but may experience higher latencies due to parallelism and scaling.

Performance Considerations

• General Purpose Mode is suitable for everyday workloads where low latency is critical but high throughput is not required.
• Max I/O Mode should be used for workloads requiring massive scalability and throughput but where the application can tolerate slightly higher latencies.
• Provisioned Throughput is useful for applications that need a constant, high level of throughput without being constrained by the amount of data in the file system.
• For a distributed file system like Amazon EFS, throughput refers to how much data can be read from or written to the file system per second.
• Amazon EFS provides different performance modes to optimize for various workloads: General Purpose for low-latency, interactive applications, and Max I/O for large, data-intensive applications requiring high throughput but can handle higher latencies.
• Bursting and Provisioned Throughput offer additional throughput capacity control, optimizing cost and performance based on the specific use case.

Explore Amazon Elastic File System (EFS), ideal for shared, scalable file storage in the AWS cloud. Learn about its high availability, security features, and suitability for various applications needing persistent storage. Discover when to use Max I/O mode and its benefits as a fully managed service.