A storage arrangement including: a first storage system having one or more first logical storage devices and a second storage system having one or more second logical storage devices, configured to: a) determine whether two or more identical contents hash values are contained in a plurality of contents hash values of said plurality of files; and b) change an access destination of a first file corresponding to a first contents hash value from among said two or more identical contents hash values, to a position of a second file corresponding to a second contents hash value if there are said two or more identical contents hash values, c) do not migrate said first file to said second storage system, and migrate said second file to said second storage system to store in any of said one or more second logical storage devices.