Patent ID: 7502907

Claim:
A method of managing volumes of a plurality of storage systems coupled to a management computer via a first network, the plurality of storage systems having volumes provided to a computer via a second network and storing data used by the computer, the plurality of storage systems including a first storage system and a second storage system, the method comprising the steps of: keeping a first characteristic table in said first storage system and a second characteristic table in said second storage system, the first characteristic table indicating a correspondence between a plurality of hint values and a plurality of characteristic values of volumes included in said first storage system, the second characteristic table indicating a correspondence between a plurality of hint values and a plurality of characteristic values of volumes included in said second storage system; obtaining from said first storage system a first hint value related to a first volume included in said first storage system when one or more of said characteristic values of said first characteristic table or one or more of said characteristic values of said second characteristic table are changed; referring by the management computer to a first characteristic value corresponding to said first hint value, the first characteristic value included in said first characteristic table and to a second characteristic value corresponding to said first hint value, the second characteristic value included in said second characteristic table; comparing said first characteristic value and second characteristic value; and migrating data from said first volume to a second volume included in said second storage system if said second characteristic value is more desirable than said first characteristic value for said first hint value as a result of the comparison.