Technique for correcting multiple storage device failures in a storage array

An apparatus to store data for correction of multiple data storage failures in a storage array, comprising:

• means for organizing the storage array as a plurality of sub-arrays, each sub-array including a set of data storage devices and a plurality of local parity storage blocks, each of the plurality of local storage blocks storing parity information for a corresponding sub-array;
• means for computing a plurality of diagonal parity sets, one diagonal parity set for each sub-array;
• means for computing a global diagonal parity by logically combining together a plurality of the diagonal parity sets;
• and
• means for storing the global diagonal parity in a plurality of global diagonal parity storage blocks.

An apparatus to store data for correction of multiple data storage failures in a storage array, comprising:

• a plurality of sub-arrays, each sub-array including a set of data storage devices and a plurality of local parity storage blocks, each of the plurality of local storage blocks to store parity information for a corresponding sub-array;
• a processor to compute a plurality of diagonal parity sets, one diagonal parity set for each sub-array;
• the processor to compute a global diagonal parity by logically combining together a plurality of the diagonal parity sets;
• and
• a disk array to store the global diagonal parity in a plurality of global diagonal parity storage blocks.

A computer readable media, comprising:

• said computer readable media containing instructions for execution on a processor for the practice of a method for storing data for correction of multiple data storage failures in a storage array, the method having the steps of,
• organizing the storage array as a plurality of sub-arrays, each sub-array including a set of data storage devices and a plurality of local parity storage blocks, each of the plurality of local storage blocks storing parity information for a corresponding sub-array;
• computing a plurality of diagonal parity sets, one diagonal parity set for each sub-array;
• computing a global diagonal parity by logically combining together a plurality of the diagonal parity sets;
• and
• storing the global diagonal parity in a plurality of global diagonal parity storage blocks.