A method of providing on-demand service through a virtual file system is implemented at a computing device. In response to receiving a request for a file associated with an instance of the virtual file system, the computing device checks the metadata of the requested file in the virtual file system to identify a first set of data blocks of the requested file that is not present at the computing device and retrieves the first set of data blocks from at least one of a plurality of storage devices associated with the virtual file system. The computing device generates a copy of the requested file using the retrieved first set of data blocks and returns the generated copy of the requested file to the requesting application or user.