The storage system includes a first storage subsystem having a first logical volume to be accessed by a host computer, and a second storage subsystem connected to the first storage subsystem and having a second logical volume to be mapped to the first logical volume. The first storage subsystem includes a memory having definition information for defining a plurality of logical paths that transfer, to the second logical volume, I/O from the host computer to the first logical volume, and a transfer mode of the I/O to the plurality of logical paths. At least two or more logical paths among the plurality of logical paths are defined as active, and the controller transfers the I/O to the at least two or more logical paths set as active.