Patent ID: 8918615

Claim:
An information storage system comprising: a plurality of host computers including a first host computer; a plurality of storage systems, which are connected to each other to enable communication with each other, including a first storage system and a second storage system; and a management system, wherein each of the plurality of storage systems includes: default storage system identification information which is the same for each of the plurality of storage systems; volume management information including a first volume identification information, which is uniquely identifying a first volume provided by a first storage system to the first host computer among the plurality of storage systems, and a first port identifier of a first port which is connected to the first volume in the first storage system; and a controller configured to return the default storage system identification information to the first host computer in response to a request from the first host computer, wherein when the second storage system receives a read or write request from the first host computer to the first volume provided by the first storage system, the second storage system is configured to transfer the read or write request to the first port of the first storage system based on the volume management information, wherein the first storage system is configured to receive the transferred read or write request and send the result of the read or write request to the second storage system, wherein the second storage system is configured to transfer the result of the read or write request to the first host computer, wherein the management system includes information indicating connectivity between each port of the plurality of storage systems and each port of the plurality of host computers, and includes information indicating capacities of the plurality of storage systems, wherein the management system is configured to: identify a second port, which is a port of the first host computer and is connected to the first port of the first storage system, based on the information indicating connectivity; and select a storage system, which is able to be connected to the identified second port of the first host computer and has remaining capacity for the first volume to be migrated from the first storage system, as a storage system of a migration destination of the first volume in the plurality of storage systems based on the information indicating connectivity and the information indicating capacities, and wherein the information storage system is configured to execute a migration of the first volume from the first storage system to the selected storage system.