Choosing a data-transfer route

A migration programme runs in three phases: discover the servers and databases in scope, migrate them with the appropriate tool, and track progress to cutover. This page covers one decision inside the middle phase — how the bulk data physically gets to AWS.

The options

Over the internet. Nothing to set up, no fixed cost, and data transfer into AWS is not charged. Bounded by the available bandwidth and by how much of it production can spare during business hours. The default for small and medium datasets with no hard deadline.

Over AWS Direct Connect. A dedicated circuit, charged by port-hour plus data transfer out. Worth it when the migration is one phase of an ongoing hybrid relationship, or when the copy must complete predictably. For a one-off migration, a hosted connection procured from a Direct Connect Delivery Partner for the duration of the project avoids committing to a circuit that will not be wanted afterwards.

With AWS DataSync, over either of the above. DataSync is not an alternative route so much as the thing that makes a route usable: parallel multi-threaded transfer, in-line compression, incremental runs and integrity checking, and a single task can saturate a 10 Gbps link.

Physical hand-off. AWS Data Transfer Terminal is a facility where a slot is booked and data is uploaded at facility speed from drives brought to site. The Snow Family devices that used to serve this need are closed to new customers.

What decides it

1. Volume. The larger the dataset, the sooner physical transfer beats the network.
2. Available bandwidth, and how much of it production can spare.
3. Deadline. A copy that can trickle for a month is a different problem from one that must land over a weekend.
4. One-off or ongoing. A recurring transfer justifies capacity that is kept; a single migration justifies capacity that is rented.
5. Security posture. Some datasets are easier to justify moving on encrypted media handed over in person than across any network.
6. Setup time. Internet transfer starts today; a Direct Connect circuit is measured in weeks.

Price the shortlist with the AWS Pricing Calculator and the current Direct Connect rates. Rates and device line-ups change often enough that any figure written down here would be wrong before it was read.

Storage Gateway is not on this list

AWS Storage Gateway is a long-term hybrid architecture, not a transfer route — the appliance stays after the migration and applications keep talking to it. DataSync does both one-off migrations and scheduled recurring transfers, so a scheduled sync is not on its own a reason to deploy a gateway. The comparison page sets out where the line falls.