AZ-305 Practice Question 10: Bulk Offline Data Migration
Microsoft Azure Solutions Architect Expert (AZ-305) · Test 1 · question 10 of 10
A broadcaster must move 320 TB of archived video from an on-premises NAS into Azure Blob Storage. The archive is effectively static; a handful of files change per week. The site has one 500 Mbps internet circuit that also carries production traffic, and the network team will not allow the migration to consume more than 20 percent of it. The archive must be readable in Azure within four weeks, and the broadcaster does not want to keep paying for hybrid connectivity once the move is finished.
Which migration approach should you recommend?
Show answer and explanation
Answer:
Work the arithmetic before choosing: 20 percent of 500 Mbps is 100 Mbps, or roughly 1 TB per day at perfect efficiency, so 320 TB over the wire takes the better part of a year. Any design that moves this archive across that circuit is disqualified by the four-week deadline. Data Box is built for exactly this shape of problem; Microsoft positions it for one-time transfers larger than 40 TB where network capacity is limited. The device is shipped to the site, filled at local-network speed with no impact on the internet circuit, and shipped back for a datacenter-side upload, and there is no residual connectivity to pay for afterwards.
Option A is the disqualified case above. Throttling AzCopy respects the network team's limit but guarantees the deadline is missed by months; the tool is not the bottleneck, the circuit is.
Option C is the most plausible distractor and still fails. Even saturating a dedicated 1 Gbps circuit end to end, 320 TB takes about a month, before adding the provisioning lead time for a new ExpressRoute circuit, which routinely runs weeks. It also builds and bills a permanent private connection to solve a one-time bulk move, which the stem explicitly rules out.
Option D confuses ongoing sync with bulk seeding. Azure File Sync is designed to keep an on-premises file server and an Azure file share in step, with cloud tiering freeing local disk. Its initial upload still crosses the same constrained circuit, so it inherits the same timeline, which is why Microsoft documents using Data Box to seed a File Sync deployment rather than seeding it over the network.
Reference: What is Azure Data Box?