AWS DataSync is a purpose-built, managed service designed to simplify and accelerate data transfers between on-premises storage systems and AWS storage services. It can directly transfer data from an on-premises NFS file system to an Amazon EFS file system. This approach provides a single, fully managed solution that automates data transfer, including scheduling, encryption, data integrity validation, and network optimization. By using DataSync over the existing Direct Connect connection with a private VIF and VPC endpoints, the company achieves a secure, high-performance, and operationally efficient replication process without needing intermediate storage like Amazon S3 or custom-coded solutions like AWS Lambda functions.

A. This option introduces unnecessary complexity and operational overhead by requiring a multi-step process (NFS -> S3 -> EFS) and custom logic (Lambda function) instead of a single, managed service.
B. AWS Storage Gateway (File Gateway) primarily provides on-premises applications with file-based access to Amazon S3. It does not directly replicate data to EFS, making it an indirect and inefficient solution for this use case.
C. While this option uses DataSync, it directs the data to S3 first, requiring a second step with a Lambda function to move it to EFS. A direct DataSync transfer to EFS is far more operationally efficient.

1. AWS DataSync User Guide

"What is AWS DataSync?": This document explicitly states that DataSync is an online data transfer service that automates moving data between on-premises storage systems (like NFS) and AWS Storage services (like Amazon EFS). It highlights features like end-to-end security and data integrity

which contribute to operational efficiency.

Source: AWS Documentation

https://docs.aws.amazon.com/datasync/latest/userguide/what-is-datasync.html

Section: "What is AWS DataSync?".

2. AWS DataSync User Guide

"Creating a location for Amazon EFS": This guide provides instructions for configuring an Amazon EFS file system as a destination location for a DataSync task

confirming the direct transfer capability from a source like NFS.

Source: AWS Documentation

https://docs.aws.amazon.com/datasync/latest/userguide/create-efs-location.html

Introduction section.

3. AWS DataSync User Guide

"Using AWS DataSync with AWS Direct Connect": This section details how to use DataSync over a Direct Connect connection. It recommends using a private virtual interface (VIF) and VPC endpoints for private

secure data transfer

which aligns with the most efficient and secure architecture.

Source: AWS Documentation

https://docs.aws.amazon.com/datasync/latest/userguide/datasync-direct-connect.html

Introduction section.

4. AWS Storage Blog

"Migrating storage with AWS DataSync": This official blog post describes common migration patterns and explicitly mentions the capability of DataSync to copy data between NFS shares and Amazon EFS file systems as a primary use case

reinforcing its suitability and efficiency for this scenario.

Source: AWS Blogs

https://aws.amazon.com/blogs/storage/migrating-storage-with-aws-datasync/

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