Patent ID: 7831687

Claim:
A storage system comprising: a first storage apparatus providing a first logical unit that stores file data; a first server that accesses 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 first computer in communication with a second server through a local area network; and a management server that holds 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 being allowed to share the file data, wherein said second server is 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 first storage apparatus to access said file data in said first logical unit in said first storage apparatus, wherein said second server determines whether said second server is permitted to access said file data available for sharing on said first logical unit, and establishes a communication path over said wide area network with said storage apparatus, and wherein when said first server and said second server share said file data and store any of said file data as buffered data at said first server or said second server, said management server requests said first server and said second server to write the buffered data into said first storage apparatus and said first server and said second server write the buffered data into said first storage apparatus; a second storage apparatus connected to said second server, wherein said second server includes file information that is used to determine whether the first file-based operation request pertains to said shared logical unit in said first storage apparatus, or to a third logical unit managed by said second server in said second storage apparatus; wherein said first server and said second server are connected via a first security protection apparatus and a second security protection apparatus, respectively, over the wide area network to a third security protection apparatus connected to said first storage apparatus, and wherein communications over said wide area network between said first server, said second server and said first storage apparatus are encrypted.