The Mechanism
RAID 5 relies heavily on complex mathematical calculations (XOR logic) to process parity data. This is typically handled by a dedicated hardware RAID controller card or system firmware.
The Impact on RAID 5
If the RAID controller card experiences an electrical surge, overheating, or a physical component failure, the array goes offline. Furthermore, a sudden power outage can result in a "Write Hole." If the system loses power precisely while writing a block of data but before it finishes writing the corresponding parity block, the data and parity become desynchronized. When power returns, the controller may read corrupted structures, leading to file system breakdown.
