Patent ID: 7185030
Filing Date: 2007-02-27
Classification: G06F,Y10S

Abstract:
1. A storage system for storing an original file and at least one format converted file of the original file comprising: a storage media; and a file conversion unit which, in response to a request to store an original file is configured to convert the original file to at least one format converted file, wherein said storage system is configured to store the original file and the at least one format converted file on said storage media, and is able to manage a relationship between the original file and the at least one format converted file to permit retrieval of either of the original file and the at least one format converted file, wherein said file conversion unit is configured to calculate a first hash value of the original file and a second hash value for each of the at least one format converted files, and wherein said storage system is configured by instructions to determine whether the original file has changed or whether the at least one format converted file has changed by reading one of said files, calculating a new hash value for the read file, and comparing said new hash value with a respective one of said first hash value if said original file is read, or comparing the new hash value with a corresponding second hash value if one of said format converted files is read.