Patent ID: 9235353
Filing Date: 2016-01-12
CPC Classification: G06F

Claim Text:
1. A storage apparatus coupled to a host computer, comprising: a plurality of storage devices including a first storage device and a second storage device whose performance is higher than that of the first storage device; and a controller configured to: provide a virtual volume including a plurality of logical areas to the host computer; allocate at least one of a plurality of storage areas in the plurality of storage devices to a logical area of the virtual volume after receiving a write request to the logical area of the virtual volume; after a first storage area is allocated to a first logical area in the virtual volume in response to a first write request to the first logical area of the virtual volume, upon receiving a read request or another write request to the first logical area of the virtual volume, execute a determination as to whether or not to migrate data in the first storage area of the first storage device to a second storage area of the second storage device based on an access frequency corresponding to the data of the first logical area; migrate the data in the first storage area of the first storage device to the second storage area of the second storage device according to a result of the determination; and allocate the second storage area of the second storage device to the first logical area in the virtual volume.