Mysterious formatting on a NAS hard drive

As far as I know, disk drives that are used in NAS solutions do not use any mysterious type of formatting, at least on the basic disk drives. However, keep in mind that disk drives accessed in NAS go through the NAS file system. The NAS solution could be an integrated appliance, a general purpose server running NAS software, a NAS gateway accessing block storage in a SAN or via direct connect, or a storage subsystem that supports mixed block and file access. Thus, if you look at a disk drive that is being used in a NAS solution, it may appear that there is some form of mysterious type of formatting when in actual fact, there isn't. What you're seeing is the specific formatting of the operating system, volume manager and file system of the server or NAS appliance that the disk is attached to. To perform data maintenance, including defragmenting and backup for recovery, you would need to access the storage via the file system or NAS management software. Hopefully, that helps to clarify the mysterious type of formatting you might have encountered.