Data protection in a random access disk array

A disk array memory system comprising

• a plurality of disks in a disk array for storage of content data and parity data in stripes, content data in a same stripe sharing parity bits of said parity data,
• a cache for caching content data prior to writing to said disk array;
• a controller configured to select a stripe for a current write operation of data from said cache, thereby to write all said content data of said current write operation and corresponding parity data on a same stripe at a same physical location, and irrespective of logical relationships of parts of said content data;
• and the controller utilizing a mapping table to map between physical locations and logical relationships of said content data.

A disk array memory method comprising

• providing a plurality of disks in a disk array,
• storing content data and parity data in stripes within said disk array, wherein content data in a same stripe shares parity bits of said parity data,
• for said array defining an array spare capacity, said array spare capacity providing a dynamic space reserve over said array to permit data recovery following a disk failure event;
• caching content data to aggregate data from multiple write operations into a single aggregated write operation prior to writing to said disk array;
• selecting a stripe having a largest spare stripe capacity;
• writing said aggregated cached data in a single write operation to said selected stripe, thereby to maximize sharing of parity bits per write operation and minimize separate parity write operations.

A disk array memory method comprising

• providing a plurality of disks in a disk array for storage of content data and parity data in stripes, content data in a same stripe sharing parity bits of said parity data,
• caching content data prior to writing to said disk array;
• selecting a stripe for a current write operation of data from said cache, thereby to write all said content data of said current write operation and corresponding parity data on a same stripe at a same physical location, and irrespective of logical relationships of parts of said content data;
• and
• utilizing a mapping table to map between physical locations and logical relationships of said content data.