System and method for dynamically resizing a parity declustered group

摘要

A storage server resizes an array of mass storage devices and distributes data blocks stored in the array of mass storage devices evenly in a declustered organization across the resized array of mass storage devices. Resizing the array of mass storage devices may include adding a new mass storage device to the array or removing a mass storage device from the array. During resizing a data block is moved from one mass storage device to another mass storage device to minimize the imbalance of parity groups shared by the new mass storage devices in the array, as well as minimize the number of data blocks to be moved to uniformly balance the load across the new mass storage device.