Patent ID: 7246212
Filing Date: 2007-07-17
Classification: G06F

Abstract:
1. A disk array apparatus comprising: a disk controller; a first disk group comprising n disk devices each of which is coupled to the disk controller; a second disk group comprising m disk devices each of which is coupled to the disk controller; wherein, in the first disk group, a first logical unit comprising plural stripes, each of which includes n−1 units data and parity data generated from the n−1 units data each stored in a different disk in the n disk devices, is formed; wherein, in the second disk group, a second logical unit comprising plural stripes, each of which includes m−1 units data and parity data generated from the m−1 units data each stored in a different disk in the in disk devices, is formed; wherein n and m are different integers; wherein original data is stored in the first logical unit and copy data of the original data is stored in the second logical unit; wherein the disk controller is configured to update the original data stored in the first logical unit and write the updated data to the second logical unit; and wherein the disk controller is further configured to read the updated data from the first logical unit so as to permit assortment of the read updated data to Logical Block Address (LBA) sets in stripes of the second logical unit that are identified as copy-necessary LBA sets.