Patent ID: 8402234

Claim:
A storage system comprising: a host apparatus inputting and outputting request for data; a migration source storage apparatus capable of being recognized from the host apparatus, the migration source storage apparatus managing one or more logical units correlated to a storage region of a physical device for storing the data; a migration destination storage apparatus in one or more logical units that is a migration destination of the one or more logical units for the migration source storage apparatus, the migration source storage apparatus capable of being recognized from the host apparatus; an editing unit for editing configuration control information relating to the one or more logical units for the migration source storage apparatus so as to match with a setting for the migration destination storage apparatus; an importing unit for importing edited configuration control information that is configuration control information edited to reflect a storage location in the migration destination storage apparatus; and an external storage apparatus including the physical device, wherein the migration source storage apparatus and the migration destination storage apparatus are connected via a path, and each has a disk cache, which can be set to an on or off condition, for temporarily storing data from the host apparatus, wherein the host apparatus is connected to the migration destination storage apparatus and the migration source storage apparatus via a path, the host apparatus outputting the input/output request by switching between the migration destination storage apparatus and the migration source storage apparatus, wherein, when the data is input to or output from the migration source storage apparatus with respect to the external storage apparatus via a path, a disk cache of the migration source storage apparatus is set to on, and a disk cache of the migration destination storage apparatus is set to off, wherein the input/output request from the host apparatus to the migration destination storage apparatus is transmitted to the external storage apparatus via the migration source storage apparatus, wherein, when the data is input to or output from the migration destination storage apparatus with respect to the external storage apparatus via a path, the disk cache of the migration destination storage apparatus is set to on, and the disk cache of the migration source storage apparatus is set to off, wherein the input/output request from the host apparatus to the migration source storage apparatus is transmitted to the external storage apparatus via the migration destination storage apparatus.