Patent ID: 8856080

Claim:
A method, comprising: during an initial backup operation at a computer system: creating a backup virtual hard drive (VHD) of a data volume at a storage device of the computer system; creating a metadata VHD corresponding to the backup VHD; storing the metadata VHD at a memory within the computer system; and transmitting the backup VHD from the computer system to a remote storage location while the metadata VHD is retained at the computer system; after completion of the initial backup operation, detecting a change to a file of the data volume; creating a differential VHD at the computer system based on the metadata VHD stored in the memory of the computer system, wherein the differential VHD indicates the change to the file; updating the metadata VHD at the computer system to reflect the change to the file; and during a subsequent backup operation at the computer system, transmitting a copy of the updated metadata VHD and the differential VHD from the computer system to the remote storage location.