Patent ID: 7975118
Filing Date: 2011-07-05
Classification: G06F

Abstract:
1. A storage system comprising: a host computer sending various kinds of requests and write data; a first storage apparatus having a first virtual volume that can be dynamically extended and that is provided to the host computer, and a first volume allocated to the first virtual volume, the first volume being a volume where data sent from the host computer is written; a second storage apparatus having a second virtual volume backing up data stored in the first virtual volume, and a second volume allocated to the second virtual volume, the second volume being a volume where data sent from the first storage apparatus is written, the first storage apparatus further including: a first transmission unit sending a data transmission switching request for switching a data transmission destination of the write data to the host computer, if data rearrangement in the first volume is executed; a first rearrangement unit rearranging data in the first volume; a difference management volume to which difference data for the write data written to the first volume is written; the host computer including a data transmission switching unit switching the data transmission destination after receiving the data transmission switching request sent from the first transmission unit, so that the write data, which was originally directed to the first virtual volume in the first storage apparatus, is sent to the second virtual volume in the second storage apparatus; wherein the first 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; if data rearrangement in the first volume is executed: the first transmission unit sends the data transmission switching request to the host computer after sending the difference data written to the difference management volume to the second virtual volume in the second storage apparatus; and the first transmission unit sends a data response performance calculation request to the second storage apparatus after the rearrangement unit executes data rearrangement in the first volume; the second storage apparatus further including: a second response performance comparison unit calculating a data response performance in the second storage apparatus; a second transmission unit sending the data response performance in the second storage apparatus to the first storage apparatus; and a second difference management volume to which difference data for the write data written to the second volume is written; the first storage apparatus further including a first response performance comparison unit: calculating a data response performance in the first storage apparatus after the rearrangement unit executes the data rearrangement in the first volume; and comparing the data response performance in the first storage apparatus with the data response performance in the second storage apparatus; if the data response performance in the first storage apparatus is higher than the data response performance in the second storage apparatus: the data transmission switching unit switches the transmission destination of the write data from the second virtual volume in the second storage apparatus to the first virtual volume in the first storage apparatus; and the first transmission unit sends the data transmission switching request to the second storage apparatus; the second transmission unit sends the data transmission switching request to the host computer after sending the difference data written to the second difference management volume to the first virtual volume in the first storage apparatus; and the data transmission switching unit switches the transmission destination of the write data from the second virtual volume in the second storage apparatus to the first virtual volume in the first storage apparatus after receiving the data transmission switching request sent from the second transmission unit.