Patent ID: 7194592
Filing Date: 2007-03-20
Classification: G06F

Abstract:
1. A storage system using load balancing among systems of varying processing performance, comprising a plurality of types of storage subsystems comprising high-performance storage subsystems with relatively high processing performance, and low-performance storage sub-systems with low processing performance relative to the high processing performance of the high-performance storage subsystems, each storage subsystem providing one or more volumes, a service-providing server which accesses each of said storage subsystems to exchange data, and a management server, connected to each of said storage subsystems and to said service-providing server, to manage each of said storage subsystems, wherein (1) said management server comprises: a collection/analysis portion which collects and analyzes information relating to states of use of each of said storage subsystems; a volume transition management portion which, based on said analyzed states of use, moves volumes with relatively high frequencies of use from said low-performance storage subsystems to said high-performance storage subsystems, and moves volumes with relatively low frequencies of use from said high-performance storage subsystems to said low performance storage subsystems; and, wherein a communication path for said volume movement is preset prior to the beginning of said volume movement only between a high-performance storage subsystem and a low-performance storage subsystem, wherein no communication path for volume movement is so preset between low-performance storage subsystems, and wherein said communication path is preset between a high-performance storage system and a low-performance storage system under the condition that a communication session is established via said preset communication path, a unique identification information management portion which sets, for the volumes of each of said storage subsystems, unique identification information which is not affected by volume movement by said volume transition management portion; (2) each of said storage subsystems comprises: an upper level interface control unit that controls data exchanges with the service-providing server; a lower level interface control unit that controls data exchanges with a plurality of memory drives; a memory unit that is shared by the upper level interface control unit and the lower level interface control unit, one or more actual volumes; a dummy volume for movement control, wherein one dummy volume is prepared for each said communication path; an unused volume secured in advance in a pool area; a copy control portion which performs volume copying spanning storage subsystems via said communication path, according to instructions from said volume transition management portion; and, an investigation portion, which collects information relating to states of use and transmits said information to said collection/analysis portion; (3) said service-providing server comprises: a volume movement monitoring portion, which receives notification relating to said volume movement from said volume transition management portion; and, an access target modification portion, which modifies the access target to a volume which has been moved in said volume movement, based on said notification and on said unique identification information; and wherein in the movement source storage subsystem, the volume to be moved is allocated to said dummy volume for movement control; in the movement target storage subsystem, said unused volume is allocated to said dummy volume for movement control; the contents of the volume to be moved, and which is allocated to said dummy volume for movement control in the movement source storage subsystem, are volume-copied via said communication path to the unused volume allocated to said dummy volume for movement control in the movement target storage subsystem; when said volume copying is completed, use of said volume-copied volume is begun; and, said moved volume is returned to said pool area as an unused volume.