--preserve_mbr
When recovering a volume over an existing one, the target volume is deleted from the disk along with its entry in the target disk MBR. Then, with this parameter, the recovered volume's entry will occupy the upper empty position in the target disk MBR. Thus, the target disk MBR is preserved. If the parameter is not specified, the recovered volume's entry will occupy the same position as in the source disk MBR saved in the backup. If the position is not empty, the existing entry will be moved to another position.