US Patent 10956079 Data resynchronization

Examples herein relate to re-synchronizing data between an upstream volume and a downstream volume, including by communicating data to the downstream volume, from a start point to an end point of the upstream volume, maintaining a first cursor to indicate data, from the start point to the first cursor, that has been communicated to and committed to persistent storage of the downstream volume, and maintaining a second cursor to indicate data, from the first cursor to the second cursor, that has been communicated to the downstream volume and buffered without yet being confirmed as committed to persistent storage of the downstream volume.