Patent ID: 7783844

Claim:
A computer system, comprising: a plurality of storage device systems including one or more remote-copy purpose logical volumes, and one or more high-rank apparatuses connected to each of said storage device systems, said plurality of storage device systems being connected to each other via a network, wherein said one or more remote-copy purpose logical volumes configure remote-copy groups, wherein said one or more remote-copy purpose logical volumes configuring said remote-copy groups being controlled such that said one or more remote-copy purpose logical volumes have same contents among said plural storage device systems, wherein shared/exclusive control using a shared logical volume which is unconscious of a remote copy being performed using said high-rank apparatuses in an environment where said remote copy is used, said high-rank apparatuses being connected to said one or more remote-copy purpose logical volumes within each of said remote-copy groups, wherein each of said high-rank apparatuses includes an arbitration-emulation control module and a SCSI-command trap module, wherein said shared/exclusive control comprises a two-step arbitration of: a first step of executing respective arbitrations within respective sites each including at least one storage device system and at least one high-rank apparatus thereby to determine respective arbitration-win high-rank apparatuses within said respective sites, and a second step of executing, among said respective sites, an arbitration among said respective arbitration-win high-rank apparatuses within said respective sites thereby to determine an arbitration-win high-rank apparatus among said respective sites, wherein said SCSI-command trap module traps a SCSI command issued from a clustering unit, issues said trapped SCSI command to said one or more remote-copy purpose logical volumes, catches a return value of said trapped SCSI command from said one or more remote-copy purpose logical volumes and issues said return value to said emulation control module based on a value indicated by said return value, and wherein said emulation control module, upon receipt of said return value of said trapped SCSI command from said SCSI-command trap module and a volume state of said remote-copy groups, causes said trapped SCSI command and said volume state of said remote-copy groups to correspond to each other in accordance with said value indicated by said return value.