A storage apparatus includes a drive unit in which a logical unit is formed, and a controller unit for accessing the logical unit by controlling the drive unit according to an access request sent from a host apparatus. The storage apparatus issues a logical unit takeover request to the other storage apparatuses, allocates a logical unit of another storage apparatus that will accept the transfer of the logical volume to its own logical unit according to a takeover approval sent from other storage apparatuses in response to the takeover request, and thereafter migrates data of the own logical unit to a logical unit of another storage apparatus. Subsequently, the path is switched so that the access request from the host apparatus is given to one of the other storage apparatuses.