Patent ID: 7395283

Claim:
A method for use with a data processing system for connection in an open system network including a data storage facility and a host device for generating commands during the processing of a host application including a first command with arguments identifying a source logical device and a destination logical device and a second command for initiating an ordered copying of data from the source logical device to the destination logical device wherein the data storage facility includes a host controller for receiving the commands, device controllers associated with each of said source and destination logical devices and means for interconnecting said device controllers, said method responding to the first and second commands by: A) in response to the first command from the host device, establishing in the data storage facility an operating environment phase by generating a data structure including the addresses of the source and destination logical devices, an operation data element for identifying the operation of the establishment phase and an operation status element designating a status of said establishment phase and data identifying each storage location in the source and destination logical devices, and B) making the source and destination logical devices available for use by host applications, C) in response to the second command from the host, testing the operation data and status elements and, in response to values of said operation and status elements that indicate that the establishment phase has been completed, initiating an ordered copying of data from the source logical device to the destination logical device by: i) updating the operation data and status elements to indicate that copying is in progress and, ii) for each storage location in the source logical device: a) copying data from each storage location in the identified source logical device to the identified destination logical device, and b) updating the status for each storage device to indicate the completion of each transfer from a storage location, and D) upon completion of said copying, updating the operation status element to indicate that the copying has been completed.