A systems administrator is troubleshooting a rackmount server with a 12-bay hot-swap drive cage. The server's RAID controller is reporting that four drives, located in bays 1 through 4, have simultaneously gone offline. The remaining drives in bays 5 through 12 are operating normally. The administrator replaced the drive in bay 1 with a known-good spare, but the controller still reports that bay as failed. The server's OS, which boots from an internal M.2 drive, is unaffected. Which of the following is the MOST likely cause of this issue?
The correct answer is a failed storage backplane. A server's drive backplane is the circuit board that connects a group of hot-swap drives to the system's storage controller and power supply. A failure in the backplane's circuitry can affect multiple drives at once, and such failures often impact physically adjacent bays, as described in the scenario (bays 1-4). Because the problem persists in the same bay even after a known-good drive was inserted, it indicates the fault lies with the shared hardware connecting the bay, not the drive itself.
RAID controller failure: A failure of the main RAID controller would typically affect all connected drives, not just a specific group. The fact that drives in bays 5-12 are functioning normally makes this cause less likely.
Incorrect RAID driver: A driver is software, and a driver-level issue is unlikely to manifest as a physical failure limited to a contiguous block of drive bays. The symptoms point more strongly to a hardware fault affecting a specific location.
Corrupted RAID configuration: A corrupted RAID configuration on the controller would affect the logical array and be reported as a configuration error, rather than causing multiple physical bays to report simultaneous drive failures.