A computer-implemented method, according to one embodiment, includes: using a supplemental data storage volume at a secondary location to track a first set of data updates to a primary data storage volume at a primary location in response to a failure event at the primary location; retrieving a second set of tracked data updates to the primary data storage volume stored in a secondary data storage volume at the secondary location; merging the second set of tracked data updates into the first set of tracked data updates in the supplemental data storage volume; and transitioning the merged data updates from the supplemental data storage volume at the secondary location to the primary data storage volume at the primary location. Other systems, methods, and computer program products are described in additional embodiments.