Method for optimizing cleaning of maps in flashcopy cascades containing incremental maps

摘要

A method for optimizing cleaning of maps in storage cascades includes determining whether a target disk of a map contains data unavailable to a downstream disk from an upstream disk in a cascade and detect whether the downstream disk has a copy of the data. Additionally, the method includes copying the data from the target disk to the downstream disk, if the target disk of the map contains data unavailable to the downstream disk from the upstream disk and the downstream disk does not have the copy of the data. Furthermore, the method includes copying the data from the target disk to the downstream disk, if the target disk of the map does not contain data unavailable to the downstream disk from the upstream disk or the downstream disk does have the copy of the data. Moreover, the method includes removing the map from the cascade.