A method for transferring a copy of data stored at a source to a remote location. The method includes storing at the source sequence of sets of changes in the data stored at the source. The method transfers to a first one of a pair of storage volumes at the remote location the most recent pair of the stored sets of changes in the sequence of data stored at the source at a time prior to such transfer. The method subsequently transferring to a second one of the pair of storage volumes at the remote location the most recent pair of the stored sets of changes in the in the sequence of data stored at the source at a time prior to such subsequent transfer.