Patent ID: 7441029

Claim:
A storage system comprising: a first storage apparatus providing a first logical unit for storing file data in a block-based format; a first server able to access a local second logical unit, said first server configured to transfer the file data from the local second logical unit over a wide area network to the first logical unit to make the file data available for sharing; a management server for holding both a storage location of the file data stored in said first logical unit of said first storage apparatus and management information used to manage access to said file data in said first logical unit, said management information being transferred from said first server to said management server in conjunction with the transfer of the file data to the first logical unit, said management information identifying the file data available for sharing with other servers and the other servers allowed to share the file data; and a first computer in communication with a second server through a local area network, said second server being configured to accept a first file-based operation request directed to the file data available for sharing via the local area network from the first computer, and send by way of the wide area network a corresponding second file-based operation request to said management server to access said file data in said first logical unit in said first storage apparatus; wherein said management server, upon determining from said management information transferred from said first server that said second server is one of said other servers permitted to access said file data available for sharing on said first logical unit, establishes a communication path over said wide area network with said second server; wherein when said first server and said second server are sharing said file data and are storing any of said file data as buffered data at said first server or said second server, management server requests said first server and said second server to write the buffered data into said first storage apparatus; wherein said file data available for sharing contained within said first logical unit is accessed by said management server using a block-based protocol in response to said second file-based operation request; wherein said management server responds to said second server using a file-based operation response, wherein said file data is shared by said first server and said second server through said wide area network.