Patent ID: 6748488
Filing Date: 2004-06-08
Classification: G06F

Abstract:
A data storage subsystem that comprises:an array of storage devices configured to store information in the form of a plurality of stripes; and a storage controller coupled to the storage devices and configured to write a plurality of code words forming each stripe to said array, wherein said plurality of code words represents a systematic Reed-Solomon mapping of a plurality of data blocks and comprises said plurality of data blocks and a distinct plurality of redundancy blocks, and wherein the storage controller is configurable to update a subset of data blocks in a target stripe by: reading original data from said subset, reading original redundancy information from the plurality of redundancy blocks in the target stripe, determining a data difference between new data and the original data, determining a redundancy difference from the data difference, applying the redundancy difference to the original redundancy information to obtain updated redundancy information, writing the new data to the subset of data blocks, and writing the updated redundancy information to the redundancy blocks in the target stripe.