Rapid regeneration of failed disk sector in a distributed database system

An apparatus for operating a Redundant Array of Inexpensive Disks (RAID) to recover from read errors comprising:

• a RAID controller connected to a disk controller, the RAID controller configured to receive a report of an unrecoverable read error at a sector associated with a particular Logical Block Address (LBAi) in a primary disk portion, and in response thereto, retrieve data from a mirror disk portion associated with the primary disk portion that contains the LBAi, and then write the same data thereby retrieved to the LBAi on the primary disk portion for which the error was specified;
• and
• a disk controller connected to the primary disk portion, the disk controller configured to detect the read error has occurred in the sector associated with the particular LBAi in the primary disk portion, and in response thereto, notify the unrecoverable read error at the LBAi, and further configured to reassign the sector originally associated with the LBAi for which the read error occurred to a spare sector in such a way that sequentially accessing the LBAi results in a fastest possible access rate.