Patent ID: 7921267

Claim:
A method for fixing data inconsistency between an original dataset stored as a first plurality of blocks on a source storage system and a mirror of the original dataset stored as a second plurality of blocks on a destination storage system, the method comprising: determining, by a destination storage system, a read-only persistent point-in-time image (RPPI) of the original dataset, wherein the minor of the original dataset is created from the RPPI of the original dataset, and wherein the RPPI of the original dataset is stored on the source storage system; receiving, by the destination storage system, a message from the source storage system confirming a relationship between the RPPI of the original dataset and the minor of the original dataset; receiving, by the destination storage system, a datastream representing the RPPI of the original dataset from the source storage system, wherein the datastream comprises a first set of metadata associated with the RPPI of the original dataset; determining, by the destination storage system, whether the minor is consistent with the datastream representing the RPPI of the original dataset by comparing the first set of metadata associated with the RPPI of the original dataset and a second set of metadata associated with the minor, wherein the second set of metadata is stored on the destination storage system; and fixing, by the destination storage system, the mirror to make the mirror consistent with the RPPI of the original dataset, responsive to the mirror being inconsistent with the datastream representing the RPPI of the original dataset, wherein only a portion of the mirror which is inconsistent is fixed.