Method and system for providing advanced warning to a data stage device in order to decrease the time for a mirror split operation without starving host I/O request processsing

摘要

A method and system for decreasing the time needed for a mirror split operation in a data storage device by preparing for the mirror split operation during a time interval between notification of an intended mirror split operation and the subsequent time of the mirror split operation. In general, local writes are processed preferentially and asynchronously with respect to corresponding mirror writes, but, after receiving a split advance warning, the data storage device controller preferentially processes backlogged mirror writes in order that the mirrored data storage units are nearly consistent at the time that the intended mirror split operation request is received.