Patent ID: 6549921
Filing Date: 2003-04-15
Classification: G06F,Y10S

Abstract:
A method for producing a point-in-time backup of data in a data processing systems having a host computer and a first data storage facility that stores data at predetermined locations in data blocks, a second data storage facility and a data backup facility, the second data storage facility operating, during a normal operating mode, to mirror in the first data storage facility in response to a copy program, said method comprising the steps of:A) disabling the copy program thereby isolating the second data storage facility from the first data storage facility while enabling the first data processing system to continue its operations with the first data storage facility, B) producing a backup of the data in the data storage facility of the second data storage facility on the backup facility, C) recording, at the first data processing system and during the backup operation, an identification of each data block in the first data storage facility that changes as a result of the operation of the data processing system, and D) upon completion of the backup operation enabling the copy program to copy data blocks from the first data storage facility to the second data storage facility corresponding to the recorded identifications thereby reestablishing the second data storage facility as a mirror of the first data storage facility.