Patent ID: 7290199

Claim:
A method for updating parity values in a disk array in association with storing new data in a parity stripe, wherein the disk array is of the type wherein the parity stripe includes at least first and second parity values related to data stored in the parity stripe by at least one parity stripe equation, wherein the first parity value is capable of being updated based upon the new data using a first constant derived from the at least one parity stripe equation, and wherein the second parity value is capable of being updated based upon the new data using a second constant derived from the at least one parity stripe equation, the method comprising: storing in a first buffer a first value representative of a product of the first constant and a delta value representative of a difference between the new data and old data previously stored in the parity stripe; updating the first parity value using the first value stored in the first buffer; storing in a second buffer a second value representative of a product of the first value stored in the first buffer and a third constant representative of a ratio of the second constant to the first constant; and updating the second parity value using the second value stored in the second buffer.