Patent ID: 8533419

Claim:
A method for controlling data write to a virtual volume, which is a virtual logical volume that conforms to Thin Provisioning, and is a logical volume configured from a plurality of virtual areas and used by a plurality of applications, the method comprising the steps of: (A) receiving a write request including write-destination information for identifying a virtual area of a write destination in the virtual volume; (B) determining whether or not the write-destination virtual area identified based on the write-destination information is an unallocated virtual area; and (C) in a case where the result of the determination of the (B) is affirmative, selecting an initial allocation medium corresponding to the request source of the write request, based on a policy, from among a plurality of media, each of which has a different performance and is configured from two or more real areas, and allocating a real area from among the real areas based on the selected initial allocation medium as the write-destination virtual area of the write request, wherein the policy is information including information representing a correspondence relationship between the applications, the media associated with the applications as initial allocation media, and request sources sending write requests and executing the applications.