Patent ID: 9122410
Filing Date: 2015-09-01
Classification: G06F

Abstract:
1. A storage system, comprising: a plurality of logical volumes; and a controller configured to manage the plurality of logical volumes, wherein the plurality of logical volumes include a primary volume, a secondary volume, a pool volume and a virtual volume, wherein the primary volume and the secondary volume are logical volumes composed of a plurality of storage areas, wherein the pool volume is a logical volume in a pool and is composed of a plurality of pool areas, wherein the virtual volume is a virtual logical volume composed of a plurality of virtual areas, and wherein the controller is configured to: manage the primary volume and the secondary volume as a replication pair, wherein the secondary volume is configured to store all data stored in the primary volume; migrate, at a predetermined first moment, the secondary volume to the virtual volume and manage the primary volume and the virtual volume as a snapshot pair, instead of the replication pair of the primary volume and the second volume; allocate, when data is written in a storage area of the primary volume, a pool area from the pool to the virtual volume constituting the snapshot pair with primary volume, and store pre-update data written on the storage area of the primary volume in the allocated pool area; and process the migration to the secondary volume by mapping, when it is determined that the data stored in storage area of the primary volume is the same as data corresponding thereto in the secondary volume, a virtual area in the virtual volume to the storage area storing the data in the primary volume, and mapping, when it is determined that the data stored in the storage area of the primary volume is different from the corresponding data in the secondary volume, a virtual area in the virtual volume to a pool area storing data migrated from the secondary volume to the virtual volume.