LOCAL FILE SERVER OPERATIVE TO TRANSFER FILE TO REMOTE FILE SERVER VIA COMMUNICATION NETWORK, AND STORAGE SYSTEM INCLUDING THOSE FILE SERVERS

摘要

A local file server, which manages a local storage device, and a remote file server, which manages a remote storage device, are connected to a communication network (for example, Internet). The local file server: (A) makes and transfers a replica of a file stored in the local storage device to the remote file server for a replication; and (B), if a first condition is satisfied, manages, as a to-be-migrated file, the file the replica of which has been transferred for the replication. Even after the completion of (B), the local file server does not delete the to-be-migrated file from the local storage device but, if a second condition is satisfied, deletes the to-be-migrated file from the local storage device.