Patent attributes
First and second virtual hard disk files are accessed. The first virtual hard disk file corresponds to a backup of a file and includes a first set of payload blocks to store data associated with the backup. The second virtual hard disk file corresponds to an incremental backup of the file and includes a second set of payload blocks to store data associated with the incremental backup. Data from a payload block of the first set of payload blocks is merged with data from a payload block of a corresponding payload block of the second set of payload blocks to form a merged payload block. The merged payload block is streamed for storage as a synthetic full backup of the first and second virtual hard disk files. The merging does not alter the first and second virtual hard disk files.