US Patent 7975118 Storage system and data rearrangement method

The first storage apparatus includes a transmission unit for sending to a host computer, if data rearrangement in a volume is executed, a data transmission switching request for switching the transmission destination of write data, and a rearrangement unit for rearranging data in the volume. The host computer includes a data transmission switching unit for switching, after receiving the data transmission switching request from the transmission unit, the transmission destination of the write data from a first virtual volume in the first storage apparatus to a second virtual volume in a second storage apparatus. The rearrangement unit rearranges data in the first volume after the data transmission switching unit switches the transmission destination of the write data from the first virtual volume in the first storage apparatus to the second virtual volume in the second storage apparatus.