The how but what about the why?
The how seems fairly straight forward and not all that different from moving much much smaller amounts of data. I'm curious about the why, ""We could see how it would be valuable to create our own storage system," Gupta said." That statement doesn't begin to get into why it was a good idea to migrate away. At what point are you limited by AWS and can do it better yourself? What limitations did they hit that couldn't be worked through with Amazon? I would think that if you have 500PB on Amazon's servers they would be willing to work with you if you have needs they aren't meeting.