What service should be used for large-scale data transfers and migrations between data centers?

The optimal choice for large-scale data transfers and migrations between data centers is Snowmobile. This service is designed specifically for transferring massive amounts of data, up to 100 petabytes at a time, securely and efficiently. Snowmobile is a physical data transfer solution that uses a shipping container-sized device that AWS delivers to your location, where you can then load your data onto it. Once the data is loaded, the Snowmobile is returned to AWS, where the data is then uploaded to your desired AWS storage service, such as Amazon S3.

This makes Snowmobile particularly suitable for scenarios where transferring data over the internet would be impractical due to either the sheer volume of data or potential constraints such as bandwidth limitations or transfer time. Its use of a secure, physical transport mechanism also ensures data integrity and security during the transfer process.

Other services, like Amazon S3, are primarily designed for data storage, rather than direct transfer, while Amazon Elastic File System (EFS) and AWS Transfer Family cater to different use cases involving file storage or transfer over established protocols, but they do not offer the same large-scale migration capabilities as Snowmobile.