In one general embodiment, a computer-implemented method 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. A second set of tracked data updates, which are updates to the primary data storage volume stored in a secondary data storage volume at the secondary location, are retrieved. The second set of tracked data updates is merged into the first set of tracked data updates in the supplemental data storage volume. The merged data updates are transitioned from the supplemental data storage volume at the secondary location to the primary data storage volume at the primary location. The secondary data storage volume is used to track further data updates to the primary data storage volume made at the primary location.