Patent ID: 8010874
Filing Date: 2011-08-30
Classification: G06F

Abstract:
1. A method for recovering from three failed data storage devices, comprising: establishing a plurality of storage devices to hold data, referred to as the data storage devices; establishing a storage device to hold row parity for the data devices, referred to as the row parity storage device, and referring to the data storage devices and the row parity storage device together as a set of storage devices; establishing a diagonal parity storage device to hold diagonal parity computed over the set of storage devices; establishing an anti-diagonal parity storage device to hold anti-diagonal parity computed over the set of storage devices; in the event of a failure of three data storage devices of the set of storage devices, choosing a first failed storage device to restore; computing a missing block of the first failed storage device using remaining storage devices of the set of storage devices, and the diagonal parity storage device, and the anti-diagonal parity storage device; and using diagonal parity restoration techniques to restore the remaining two failed storage devices.