Patent ID: 8086911

Claim:
A method for increasing the efficiency of a parity scrub of an array of storage devices in a clustered storage system that includes a plurality of storage systems, the method comprising: securing the array, wherein a master storage system of the clustered storage system secures the array by regulating access to the array during the parity scrub; distributing at least one task of the parity scrub from the master storage system to at least one non-master storage system selected by the master storage system from the plurality of storage systems, the at least one non-master storage system accessing the array for purposes of the parity scrub and not for servicing I/O requests from a client; and determining, by the master storage system, validity of a stored parity value, wherein validity is determined by computing data in the array upon accessing a subset of storage devices and using a result of the at least one task performed by the at least one non-master storage system; and if the stored parity value is not valid, generating, by the master storage system, a new parity value and storing the parity value in the array.