Patent ID: 8140789

Claim:
A method for remote backup, in a storage system in which a parent storage device including a plurality of first disk devices is arranged at a master site, and a plurality of child storage devices including a plurality of second disk devices are arranged at a remote site, and the patent storage device and the child storage devices are remotely connected for communications by an external connection, the method comprising: arranging, in the parent storage device, a primary logical volume configured by integrating a plurality of first logical units prepared on the plurality of first disk devices and provided to a host computer, and a secondary logical volume configured by integrating a plurality of second logical units, the plurality of second logical units provided by the plurality of the child storage devices, the primary logical volume and the secondary logical volume together comprising a copy pair; carrying out a remote copy backup process of the primary logical volume to the plurality of child storage devices, by copying data stored in the plurality of first logical units in the primary logical volume to the plurality of second logical units in the plurality of child storage devices through the secondary logical volume; storing management information in the respective plurality of second logical units, the management information including first management information indicating relationship between the second logical volume and the plurality of second logical units and second management information indicating which of the plurality of child storage devices stores each of the plurality of second logical units; and wherein when the parent storage device is damaged, specifying one of the child storage devices which stores one or more second logical units in the plurality of second logical units as an integration destination; copying data stored in other second logical units in other child storage devices to the specified child storage device by referring to the management information stored in the one or more second logical units in the specified child storage device; and configuring, in the specified child storage device, a third volume by integrating the one or more second logical units and the copied other second logical units, and providing the integrated third logical volume to the host computer.