A method and system for re-synchronizing a broken asynchronous data mirror while preserving data that is unique to either a first volume or second volume making up the mirror are disclosed. According to an embodiment of the present invention, a common data recovery point is determined. Based on the common data recovery point, data unique to a first volume is identified and sequestered by, for example, copying the unique data to a third volume on a re-synchronization data storage device. Next, that unique data is eliminated. Finally, data unique to the second volume is identified based on the common data recovery point. The data unique to the second volume is copied to the first volume, thereby synchronizing the two volumes.