Patent ID: 7254684

Claim:
A data duplication method which duplicates data being stored in a storage subsystem connected to a computer, wherein said computer includes a processor unit and a storing unit, and said storage subsystem includes a plurality of storage media managed as a plurality of volumes, said method comprising: a first storing step that causes said storing unit to store an identification information list indicative of identification information for identifying each of the plurality of volumes to be supplied to an application program which is processed by the computer, a second storing step that causes said storing unit to store a first duplication definition information which stores identification information indicative of a copy origin volume and identification information indicative of a copy destination volume, an identification information reading step which reads out from the storing unit the identification information list, a first reading step which reads out from the storing unit, a first duplication definition information, a first comparing step which compares the identification information list read out in the identification information reading step, and the first duplication definition information read out in the first reading step, an addition step in which when there exists first identification information that is stored in the identification information list but not stored in the first duplication definition information in the first comparing step, a copy destination volume of a volume identified by the first identification information is selected according to a predetermined selection condition, the first identification information and the identification information of the copy destination volume thus selected are added to the first duplication definition information, and data in the volume identified by the first identification information of the copy origin volume is copied to the copy destination volume thus selected, and a deletion step in which when there exists second identification information that is not stored in the identification information list but is stored in the first duplication definition information in the first comparing step, the second identification information and identification information of a copy destination volume, which is a copy destination of a volume identified by the second identification information, are deleted from the first duplication definition information, and copying the data of the volume identified by the second identification information is stopped.