US Patent 9785647 File system virtualization

Systems, methods, and media file system virtualization. Exemplary methods may include rendering a sparse file system and creating a block map for the sparse file system. The block map may include a map record for each file record included in the sparse file system. A map record may include extents for blocks associated with a file record, the map record providing a mapping between allocated block sectors for a file record in the sparse file system and corresponding blocks associated with one or more data sources.