Patent ID: 7865682
Filing Date: 2011-01-04
Classification: G06F

Abstract:
1. A remote copy system comprising: a plurality of primary storage systems, wherein each of the plurality of primary storage systems comprises a first controller and a source logical volume coupled to said first controller; and a plurality of secondary storage systems, wherein each of the plurality of secondary storage systems comprises a second controller, a memory, a cache memory and a target logical volume storing copy data of a primary logical volume, wherein the first controller of each of said primary storage systems comprises: wherein the second controller of each of said secondary storage systems comprises: wherein one said second controller of said plurality of secondary storage systems obtains the section numbers stored in each said memory of each of the plurality of secondary storage systems and commands all of the plurality of secondary storage systems to reflect the write data having section number values smaller than the smallest section number value obtained by the write data reflecting unit to the target logical volume, in an order of the sequential numbers, wherein the first controller further comprises a control memory that stores the section numbers, wherein the first controller updates the section numbers stored in the control memory to values incremented by 1, wherein the first controller of each of said plurality of primary storage systems puts processing of write requests on hold when a hold command is received from a host computer, wherein after the first controller of each of the primary storage systems updates the section numbers, the first controller of each of the plurality of primary storage systems cancels the hold on the processing of write requests and creates write-data management information by using updated section numbers when the write-data receiving unit receives write data from a host computer, wherein management software is executed in a host computer, wherein said hold command is issued by said management software to each said first controller of said plurality of primary storage systems, after a report of completion of putting the processing of write requests on hold is received from each said first controller of said plurality of primary storage systems, a command for updating a section number is issued to each said first controller of the plurality of primary storage systems by said management software, and wherein after a report of the completion of the section number update is received from each said first controller of said plurality of primary storage systems, a command for canceling the hold on the processing of write requests is issued to each said first controller of said plurality of primary storage systems by the management software.