A ghosting filter on a computing device receives a read command for a requested range of data of a ghosted file. The requested range is categorized into first segments present in the ghosted file, second segments pending to be reconstituted from an alternate location to the ghosted file, and third segments...http://www.google.de/patents/US7506004?utm_source=gb-gplus-sharePatent US7506004 - Moving data from file on storage volume to alternate location to free space
