1. A file storage system comprising: a remote file server for managing a remote storage device; a local file server for managing a local storage device; and a network for communicating file data between the remote file server and the local file server; wherein the remote file server comprises: one or more file devices; one or more file storage subsystems; and one or more client devices; wherein the file storage subsystem comprises: one or more processors; a memory; and a plurality of virtual computers for controlling the processor and the memory as a virtual logical device, each of the plurality of virtual computers managing file data; and wherein the virtual computer is caused to execute one or more of the following operations: a first file data access from the file device to the remote storage device; a second file data access between the client device and the remote storage device; and a third file data access between the remote storage device and the local storage device.