I've successfully migrated the disks from my old Drobo S to my Drobo 5D thunderbolt. As long as your firmware is up to date it's easy to pop the drives out in order and pop them back in in order to the new drobo. The issue I ran into when trying to migrate the first time around was the new drobo was not auto updating the firmware so they sent me the proper firmware and I did it manually and BAM it worked right away!!! | Fro Knows Photo