Correct options:
Use AWS DataSync to migrate existing data to Amazon S3 and then use File Gateway to retain access to the migrated data for ongoing updates from the on-premises applications
AWS DataSync is an online data transfer service that simplifies, automates, and accelerates copying large amounts of data to and from AWS storage services over the internet or AWS Direct Connect.
AWS DataSync fully automates and accelerates moving large active datasets to AWS, up to 10 times faster than command-line tools. It is natively integrated with Amazon S3, Amazon EFS, Amazon FSx for Windows File Server, Amazon CloudWatch, and AWS CloudTrail, which provides seamless and secure access to your storage services, as well as detailed monitoring of the transfer. DataSync uses a purpose-built network protocol and scale-out architecture to transfer data. A single DataSync agent is capable of saturating a 10 Gbps network link.
DataSync fully automates the data transfer. It comes with retry and network resiliency mechanisms, network optimizations, built-in task scheduling, monitoring via the DataSync API and Console, and CloudWatch metrics, events, and logs that provide granular visibility into the transfer process. DataSync performs data integrity verification both during the transfer and at the end of the transfer.
How DataSync Works: https://aws.amazon.com/datasync/
AWS Storage Gateway is a hybrid cloud storage service that gives you on-premises access to virtually unlimited cloud storage. The service provides three different types of gateways – Tape Gateway, File Gateway, and Volume Gateway – that seamlessly connect on-premises applications to cloud storage, caching data locally for low-latency access. File gateway offers SMB or NFS-based access to data in Amazon S3 with local caching.
The combination of DataSync and File Gateway is the correct solution. AWS DataSync enables you to automate and accelerate online data transfers to AWS storage services. File Gateway then provides your on-premises applications with low latency access to the migrated data.
Incorrect options:
Use AWS DataSync to migrate existing data to Amazon S3 as well as access the S3 data for ongoing updates - AWS DataSync is used to easily transfer data to and from AWS with up to 10x faster speeds. It is used to transfer data and cannot be used to facilitate ongoing updates to the migrated files from the on-premises applications.
Use File Gateway configuration of AWS Storage Gateway to migrate data to Amazon S3 and then use S3 Transfer Acceleration for ongoing updates from the on-premises applications - File Gateway can be used to move on-premises data to AWS Cloud, but it not an optimal solution for high volumes. Migration services such as DataSync are best suited for this purpose. S3 Transfer Acceleration cannot facilitate ongoing updates to the migrated files from the on-premises applications.
Use S3 Transfer Acceleration to migrate existing data to Amazon S3 and then use DataSync for ongoing updates from the on-premises applications - If your application is already integrated with the Amazon S3 API, and you want higher throughput for transferring large files to S3, S3 Transfer Acceleration can be used. However DataSync cannot be used to facilitate ongoing updates to the migrated files from the on-premises applications.
Reference:
https://aws.amazon.com/datasync/features/