Work out migration data transfer time instantly with clear inputs, formula shown and shareable results.
Bulk data migration over the network is often far slower than intuition suggests: 400 TB over a gigabit link at 60 percent usable throughput takes over two months. Physical transfer appliances ship tens of terabytes each and complete in about a week regardless of volume, which is why they exist — the crossover is usually somewhere around 10 to 20 TB per available gigabit.
Transfer time
effective throughput = link rate x usable share; days = data bits / (throughput x 86400); appliances = ceil(data / appliance capacity)
Production traffic must continue, and TCP over a long path rarely achieves full line rate without tuning. Sixty percent is an optimistic-realistic planning figure.
Yes, and it should be for anything large. Seed with a bulk copy or appliance, then sync deltas continuously until cutover, which reduces the final switchover window to minutes.