Patent ID: 8819674

Claim:
A method for a virtual machine to access data from a virtual device, the method comprising: attaching the virtual device to the virtual machine, wherein the virtual device is backed by an image comprising file system metadata stored in accordance with a structure of a file system supported by the virtual device and data for files indicated by the file system metadata as being stored at sector offsets in the image are stored separate from the image, and wherein the image stores a mapping table including mappings from sector offsets in the image to locations storing data for files stored separately from the image; receiving a read request for a block of data corresponding to one of the files from the virtual device; accessing a file system record associated with the read request in a directory located in the image, wherein file system metadata in the file system record includes a sector offset in the image for the file corresponding to the block of data, and wherein the sector offset is a first location in the image; accessing the mapping table to map the sector offset to a second location storing the file for the block of data that is separate from the image; and retrieving the requested block of data from the second location.