| 摘要 |
<p>In response to a state transition command relating to paired volumes, an appropriate physical device can be applied to a page of each volume. A plurality of logical devices which form logical storage areas of a plurality of physical devices having different performances, are layered corresponding to the performance of the physical devices to define pool volumes, and areas of the original logical volume, the duplicate logical volume, and the pool volume are respectively divided into original side pages, duplicate side pages, and pool side pages, and are controlled by a controller. When the controller receives a command relating to pair formation from a host computer, pool side pages which belong to the same layer are allocated to the original side page and the duplicate side page, and thereafter, when the controller receives a state transition command relating to the pair, allocation is performed so that a pool side page allocated to the duplicate side page is in a different layer from a pool side page allocated to the original side page.</p> |
