Patent ID: 8832370

Claim:
A data storage system, comprising: at least three storage devices having a plurality of groups of corresponding storage areas among the at least three storage devices, the at least three storage devices including: a first storage device storing data associated with a first unique data volume and controlled by a first processing system, a second storage device storing data associated with a second unique data volume and controlled by a second processing system, and a third storage device having a parity storage area and controlled by a third processing system; a first group of corresponding storage areas being defined by at least a first data storage area of the first storage device, a first data storage area of the second storage device and the parity storage area of the third storage device such that the parity storage area includes parity information generated based on data associated with the first unique data volume and data associated with the second unique data volume, and a second group of corresponding storage areas being defined by at least a second data storage area of the first storage device and a second storage area of the second storage device, wherein the data storage system is operable to: receive a request to write new data to a location within the first data storage area of the first storage device, determine, using the first processing system, an exclusive-or of the new data and old data currently stored at the location; transmit a result of the exclusive-or from the first processing system to the third processing system; determine, using the third processing system, a new parity value representing an exclusive-or of the result and an old parity value associated with the location; and replace the old parity value with the new parity value.