A:Answer RAID 1 is mirroring, meaning that each drive in the array would be identical. If one drive goes down, it can be replaced, and initialized. In a nutshell, yes, they are hot-swapable. The whole point of RAID is to provide for redundancy. However, if you were using this device as a 4TB storage location, without utilizing RAID, if a drive went down, you would lose everything on it.