Patent ID: 8291161
Filing Date: 2012-10-16
Classification: G06F

Abstract:
1. A method for accessing data in a physical storage-device array comprising a plurality of storage devices, wherein the physical storage-device array has a plurality of sector levels, each sector level containing one sector on each storage device in the array at corresponding addresses across the storage devices, the accessing is a read or a write operation, and the method comprises: (a) receiving a request to access data in the physical storage-device array, the request including a logical storage device identifier corresponding to a first RAID level and a parity rotation index, wherein the first RAID level is RAID-5; (b) deriving, from the logical storage device identifier corresponding to the first RAID level and the parity rotation index, a logical storage device identifier corresponding to a second RAID level, wherein: the second RAID level is RAID-4; and deriving the logical storage identifier corresponding to the second RAID level comprises: (c) deriving, from the logical storage device identifier corresponding to the second RAID level, a physical storage device identifier; and (d) accessing the data in the storage device identified by the physical storage device identifier.