Patent ID: 7840838

Claim:
A method for operating a Redundant Array of Inexpensive Disks (RAID) to recover from read errors comprising: in a RAID controller, receiving a report of an unrecoverable read error at a sector associated with a particular Logical Block Address (LBA i ) in a primary disk portion; retrieving data from a mirror disk portion associated with the primary disk portion that contains the LBA i ; writing the same data thereby retrieved to the LBA i on the primary disk portion for which the error was specified; and further comprising: in a disk controller, detecting the read error has occurred in the sector associated with the LBA i in the primary disk portion; notifying the unrecoverable read error at the LBA i ; and reassigning the sector originally associated with the LBA i for which the read error occurred to a spare sector in such a way that sequentially accessing the LBA i results in a fastest possible access rate.