Local file server transferring file to remote file server via communication network and storage system comprising those file servers

摘要

A remote file server managing a remote storage device and a local file server managing a local storage device are coupled to a communication network (e.g. the Internet). The local file server (A) replicates a file in the local storage device to the remote file server and, (B) if a first condition is satisfied, manages the replicated file which is the file from which the data is replicated as a migration target file. The local file server, even if the (B) is completed, does not delete the migration target file from the local storage device and, if the second condition is satisfied, deletes the migration target file from the local storage device.

主权项

1. A file server which is a local file server that is coupled to a communication network to which is coupled to a remote file server managing a remote storage device and that manages a local storage device, the file server comprising:
a first communication interface device which is coupled to the communication network; a second communication interface device which is coupled to a user terminal for sending an access request that is either a read request or a write request specifying a file, and which is configured to receive the access request from the user terminal; and a processor which is coupled to the first and second interface devices, wherein the processor is configured to: (A) transfer a file in the local storage device to the remote file server; (B) manage the transferred file as a migration target file; (C) not delete the migration target file from the local storage device even when the (B) is completed, and delete the migration target file from the local storage device when a certain length of time has passed from the last access time when free capacity of the local storage device falls below a specified threshold; (K) acquire, from the remote file server, upon receiving a write request with respect to a stub of the migration target file that has been deleted from the local storage device, a file managed by the remote file server which is the link destination identified from this stub; (L) store the acquired file in the local storage device; and (M) update the acquired file in accordance with the write request received in the (K); and release the stub when performing the (K).