Patent ID: 8316198
Filing Date: 2012-11-20
Classification: G06F,Y10S

Abstract:
1. A storage system comprising: a first storage system including a first plurality of disk drives and a first controller managing the first plurality of disk drives as a first volume and a second volume; and a second storage system including a second plurality of disk drives and a second controller managing the second plurality of disk drives as a third volume and a forth volume, the fourth volume configured to form a first copy pair with the first volume and storing copy data of data stored in the first volume, wherein, if the first copy pair is an asynchronous remote copy pair, when the first storage system receives a write command to the first volume from a host computer, the first controller writes data of the write command to the first volume and further writes the data of the write command to the second volume, the second controller of the second storage system manages to read the data of the write command from the second volume and writes the data of the write command to the fourth volume via the third volume, wherein the storage system is adapted to change the first copy pair from the asynchronous remote copy pair to a synchronous remote copy pair, and wherein before beginning synchronous remote copy between the first volume and the fourth volume, the storage system examines the second volume and the third volume and compares data stored in the second volume and the third volume to the fourth volume.