Patent ID: 7480779

Claim:
A storage system comprising a disk drive for storing data and a control unit connected to the disk drive for controlling data read/write from/to volumes set in the disk drive, wherein the control unit comprises a processor and a memory, the memory storing a program for controlling data read/write from/to the volumes and program for controlling copying and restoring data between the volumes, wherein the volumes include a first volume and a second volume, the first volume storing data that can be copied to the second volume, and wherein, after the copying is finished, the control unit consults a first meta data associated with data stored in a first block of the first volume, consults, in a case where the consulted first meta data including information indicating that the data stored in the first block of the first volume is prohibited from being updated for a given period, a meta data for a block that follows the first block of the first volume, and restores, in a case where the consulted first meta data does not include information indicating that the data stored in the first block of the first volume is prohibited from being updated for a given period, data stored in the second volume into the first volume by copying data stored in a second block, which is associated with the first block of the first volume, and is located in the second volume, to the first block of the first volume; wherein the control unit compares data stored in the first block of the first volume with data stored in the second block of the second volume, and sets, in a case where the data stored in the first block of the first volume does not coincide with the data stored in the second block of the second volume, information indicating of a failure to the first meta data.