US Patent 8719286 System and method for block-based subtree virtual machine backup

Techniques for virtual machine backup are described herein. According to one embodiment, a source virtual machine (VM) disk file associated with a VM is parsed to generate metadata representing files stored in a virtual storage device of the VM, where the VM is one of one or more VMs hosted by a VM monitor (VMM). In response to a request to back up a subdirectory of one or more files stored in the source VM disk file, file records of the one or more files of the requested subdirectory are identified based on the metadata. The identified file records associated with the subdirectory are backed up from the source VM disk file to a target VM disk file, without having to back up remaining files in the source VM disk file.