Storage unit generation of redundancy information in a redundant storage array system

In a redundant storage array system including an array controller for receiving a write command, and a plurality of failure independent data storage units for storing data and redundancy information in the form of blocks, at least one of the storage units including a local processing means for creating error correction code blocks, a method for improving the generation of redundancy information and the storage of data and redundancy information, including the steps of:

• a. reading an old data block from a first data storage unit;
• b. receiving a sum block which is a composite of a new data block and the old data block in a second data storage unit, the second data storage unit having a processing means for creating error correction code blocks;
• c. reading an old error correction code block corresponding to the old data block from the second data storage unit;
• d. creating a new error correction code block within the second data storage unit from the old error correction code block and the sum block;
• e. storing the new error correction code block in the second data storage unit;
• and
• f. storing the new data block in the first data storage unit.

A redundant storage array system comprising an array controller for receiving a write command, and a plurality of failure independent data storage units for storing data and redundancy information in the form of blocks, wherein:

• a. at least one of the storage units is a disk-type storage unit including:
• (1) a plurality of read/write means, at least one read/write means for reading data from the storage unit and at least one read/write means for writing data to the storage unit;
• and
• (2) a local processing means for locally generating and locally storing a new redundancy block derived from a corresponding new data block, a corresponding old data block, and a corresponding old redundancy block by combining the old data block, the new data block, and the old redundancy block within the local processing means.

In a redundant storage array system including a plurality of failure independent data storage units for storing data and redundancy information in the form of blocks, at least one of the storage units including a local processing means for creating error correction code blocks, a first read/write means for reading data, and a second read/write means for writing data, a method for improving the generation of redundancy information and the storage of data and redundancy information, including the steps of:

• a. reading an old data block from a first data storage unit;
• b. receiving a sum block which is a composite of a new data block and the old data block in a second data storage unit, the second data storage unit having a processing means for creating error correction code blocks, a first read/write means for reading data, and a second read/write means for writing data;
• c. reading with the first read/write means an old error correction code block corresponding to the old data block from the second data storage unit;
• d. creating a new error correction code block within the second data storage unit from the old error correction code block and the sum block;
• e. writing with the second read/write means the new error correction code block in the second data storage unit;
• and
• f. storing the new data block in the first data storage unit.