The Mechanism
RAID 10 relies on a controller (usually a high-end PCIe hardware card or enterprise software) to map the nested architecture. The controller must keep track of which physical disks form the mirrored pairs (RAID 1) and how those pairs are sequentially striped (RAID 0).
The Impact on RAID 10
If the controller card overheats, experiences a power surge, or suffers a firmware corruption, it loses its array metadata—the master map of the architecture. Even if all physical hard drives are completely healthy, the system will no longer recognize how to stitch the stripes and mirrors together.
Note: Unlike a simple RAID 1 array, you cannot plug a single drive from a RAID 10 array directly into a standard PC to read the files, because the data on that drive is still just a fragmented piece of a larger RAID 0 stripe.
