Patent ID: 7844575

Claim:
A data migration method in a computer system manages an operation of a first storage device having one or more logical devices and an on-line data sync unit, and manages an operation of a business server by using a storage management server, the first storage device, the business server and the storage management server being interconnected via a network, the data migration method migrating the logical device possessed by the first storage device to a second storage device having one or more logical devices when the second storage device is additionally installed, the data migration method comprising steps of: copying data and configuration information of all logical devices possessed by the first storage device, to the second storage device, by using the on-line data sync unit; stopping the application on the business server which accesses the first storage device; displaying a screen for an administrator to make a selection as to whether each logical device possessed by the first storage device is retained in the first storage device or migrated to the second storage device; upon reception of a migration command that is based on the selection made by the administrator, deleting from the first storage device the data and the configuration information of each logical device possessed by the first storage device and selected by the administrator to be migrated to the second storage device; upon reception of a retention command that is based on the selection made by the administrator, deleting from the second storage device the data and the configuration information of each logical device possessed by the second storage device and selected by the administrator to be retained in the first storage device; reactivating the application to allow the application to access the logical devices of the first storage device and the second storage device; restricting the application on the business server so as not to access the logical device possessed by the second storage device; synchronizing data of the first storage device and the second storage device during a predetermined period, and confirming that an initial defect does not exist in the second storage device; and upon reception of the migration command that is based on the selection made by the administrator, restricting the application on the business server from accessing each logical device possessed by the first storage device and selected by the administrator to be migrated to the second storage device, and allowing the application on the business server to access each logical device possessed by the second storage device and to which each logical device possessed by the first storage device is migrated, based on the selection by the administrator.