Embodiments of the present invention provide a mechanism for converting an existing mirror relationship between an original dataset at a source storage system and a copy of the original dataset at a destination system to a new mirror without discarding the existing copy of the original dataset and without transferring data to create a new dataset to replace the copy of the original dataset at the destination storage system. Rather, a directory structure (including file attributes) of the source storage system is transferred to the destination storage system and a comparison is made to identify file attributes at the destination system that match the transferred file attributes. If a match is found, a mapping between the matched file attributes is created. Subsequent updates to the destination storage system can be done using a technique other than the one that was used to create a copy of the source dataset.