Patent ID: 8583864

Claim:
A computer system comprising: a first storage apparatus including a first processor configured to provide at least a first virtual volume and a second virtual volume to a computer, a second storage apparatus coupled to the first storage apparatus and including a second processor configured to be capable of controlling start and stop of rotation of a plurality of first disk drives and to provide a first logical volume being configured with the plurality of first disk drives to the first storage apparatus, and a third storage apparatus coupled to the first storage apparatus and including a third processor configured to be incapable of controlling start and stop of rotation of a plurality of second disk drives and to provide a second logical volume being configured with the plurality of second disk drives to the first storage apparatus, wherein the first processor is configured to make the first logical volume in the second storage apparatus correspond to the first virtual volume and to make the second logical volume in the third storage apparatus correspond to the second virtual volume depending on attributes or a purpose of the first and second virtual volumes, wherein the first processor is configured to allocate a first storage region in the first logical volume to the first virtual volume or a second storage region in the second logical volume to the second virtual volume in response to receiving a write request to the first virtual volume or the second virtual volume from the computer for storing data corresponding to the write request, wherein the first processor is configured to stop the second virtual volume in response to receiving an external request to stop the second virtual volume and to migrate data in a plurality of second storage regions held as data in the second virtual volume to one or more first storage regions which are in a plurality of first storage regions in the first logical volume and have not been allocated to the first virtual volume, wherein the first processor determines whether the first virtual volume corresponding to the first logical volume has been stopped and, in a case of a determination that the first virtual volume has been stopped, instructs the second storage apparatus to stop the first logical volume, and wherein the second processor stops the first logical volume and stops rotation of the plurality of first disk drives composing the first logical volume in response to receiving the instruction from the first storage apparatus.