Access to Data for Virtual Devices

One embodiment of the present invention is a method for a virtual machine to access data from a virtual device, the method including: (a) attaching the virtual device to the virtual machine with a backing store that is a virtual image of a file system conforming to a predetermined file system format, wherein: (i) file system data is stored in one or more files, (ii) the virtual image includes metadata stored apart from the file system data, which metadata corresponds to the predetermined file system format, (iii) the metadata includes one or more directory records, and (iv) the one or more directory records include information that points directly or indirectly to the file system data; (b) issuing a read request for a block of data from the file system as if stored in the predetermined file system format; (c) accessing the metadata and determining the location of the requested block of data in the file system data; and (d) retrieving the requested block of data from the file system data.