STORAGE SYSTEM AND ITS FILE MANAGEMENT METHOD

• US 20110167045A1
• Filed: 01/05/2010
• Published: 07/07/2011
• Est. Priority Date: 01/05/2010
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Okamoto, Takuya
• Application Number:
  US12/669,166
• Publication Number:
  US 20110167045A1
• Time in Patent Office: Days
• US Class Current: 707/661
• CPC Class Codes: G06F 16/1824 implemented using Network-attached Storage [NAS] architecture distributed or networked storage systems G06F3/067; protocols for distributed storage of data in a network H04L67/1097

Abstract

A storage system capable of providing a referral target file to a file referral requestor client even if a file referral request is made before migration. When a file server 12 registers a file 26 in a storage apparatus 14, it sends metadata 28 added to the file 26 to an archive server 16, and the archive server 16 creates a stub 30 based on the received metadata 28, and registers the metadata 28 and the stub 30 in the storage apparatus 18. If the archive server 16 receives a file referral request before migration and determines that the storage destination of the file 26 is the storage apparatus 14 based on the stub 30, it requests the file server 12 to execute the migration, receives the file 26 in the storage apparatus 14 from the file server 12, and provides the file 26 to a referring client 22.

Claims

1. A storage system, comprising:

a first memory device for storing data concerning a plurality of files;

a first server for controlling the input and output of data to and from the first memory device;

a second memory device to become a migration destination of data stored in the first memory device; and

a second server for sending and receiving data to and from the first server via a network, and controlling the input and output of data to and from the second memory device,

wherein, when the first server receives a file registration request from a file registration requestor client, the first server stores a file that was input pursuant to the file registration request and metadata added to the file in the first memory device, sends the metadata to the second server,

wherein, when the second server receives the metadata that was sent from the first server, the second server creates a stub as referral information for accessing a file corresponding to the received metadata based on the received metadata, stores the created stub and the received metadata in the second memory device, and, upon subsequently receiving a file referral request from a file referral requestor client, searches for the stub and the metadata stored in the second memory device according to the file referral request, determines a storage destination of a referral target file as a target of the file referral request based on the search result, and provides the referral target file existing in the determined storage destination to the file referral requestor client.

2. The storage system according to claim 1,

wherein the second server is an archive server which, upon receiving the file referral request, searches for the stub and the metadata stored in the second memory device according to the file referral request,

determines whether a referral target file as a target of the file referral request exists in the second memory device based on the search result of the metadata,

acquires the referral target file from the second memory device upon determining that the referral target file exists in the second memory device,

provides the acquired referral target file to the file referral requestor client,

determines whether the referral target file exists in the first memory device based on the search result of the stub upon determining that the referral target file does not exist in the second memory device, and

requests the first server as a file server to send the referral target file upon determining that the referral target file exists in the first memory device,

wherein the first server acquires the referral target file, which was designated in the send request from the second server, from the first memory device, and sends the acquired referral target file as a migration target file to the second server, and

wherein, when the second server receives the migration target file from the first server, the second server provides the received migration target file as the referral target file to the file referral requestor client, and stores the received migration target file in the second memory device.

3. The storage system according to claim 1,

wherein, when the second server determines that the storage destination of the referral target file is the first memory device, the second server requests the first server to process the referral target file among the files existing in the first memory device as a migration target file to become a migration target,

wherein, in response to a request from the second server, the first server sends the referral target file among the files existing in the first memory device as a migration target file to the second server, and

wherein, when the second server subsequently receives the migration target file from the first server, the second server provides the received migration target file as the referral target file to the file referral requestor client.

4. The storage system according to claim 1,

wherein, when the second server determines that the storage destination of the referral target file is the first memory device, the second server requests the first server to process the referral target file among the files existing in the first memory device as a migration target file to become a migration target,

wherein, in response to the request from the second server, the first server acquires the referral target file from the first memory device, and sends the acquired referral target file as the migration target file to the second server, and

wherein, when the second server receives the migration target file from the first server, the second server provides the received migration target file as the referral target file to the file referral requestor client, and

stores the received migration target file in the second memory device.

5. The storage system according to claim 4,

wherein, when the second server stores the received migration target file in the second memory device, the second server changes contents of a stub corresponding to the received migration target file to referral information showing access to the migration target file stored in the second memory device.

6. The storage system according to claim 1,

wherein, when the file input together with the file registration request becomes a migration target, the first server sends a migration target file that became the migration target to the second server, and

wherein, when the first server sends the migration target file to the second server as the migration destination, the first server creates a stub as referral information for accessing the migration target file of the migration destination based on metadata corresponding to the migration target file that was sent to the migration destination, and stores the created stub in the second memory device upon associating the created stub with metadata corresponding to the migration target file that was sent to the migration destination.

7. The storage system according to claim 6,

wherein, when the first server receives a file referral request from the file referral requestor client, the first server searches the stub and the metadata stored in the first memory device according to the file referral request, determines a storage destination of a referral target file as a target of the file referral request based on the search result, and

provides the referral target file existing in the determined storage destination to the file referral requestor client.

8. The storage system according to claim 7,

wherein, when the first server determines that the storage destination of the referral target file is the second memory device, the first server requests the second server to process the referral target file among the files existing in the second memory device as the migration target file,

wherein, in response to the request from the first server, the second server acquires the referral target file from the second memory device, and sends the acquired referral target file as the migration target file to the first server, and

wherein, when the first server receives the migration target file from the second server, the first server provides the received migration target file as the referral target file to the file referral requestor client, and stores the received migration target file in the first memory device.

9. A file management method of a storage system comprising a first memory device for storing data concerning a plurality of files, a first server for controlling the input and output of data to and from the first memory device, a second memory device to become a migration destination of data stored in the first memory device, and a second server for sending and receiving data to and from the first server via a network, and controlling the input and output of data to and from the second memory device,

wherein the first server comprises:

a step of storing a file that was input pursuant to the file registration request and metadata added to the file in the first memory device and sending the metadata to the second server upon receiving a file registration request from a file registration requestor client,

wherein the second server comprises;

a step of creating a stub as referral information for accessing a file corresponding to the received metadata based on the received metadata upon receiving the metadata that was sent from the first server;

a step of storing the stub that was created at the creation step and the received metadata in the second memory device;

a step of searching for the stub and the metadata stored in the second memory device according to the file referral request upon subsequently receiving a file referral request from a file referral requestor client;

a step of determining a storage destination of a referral target file as a target of the file referral request based on the search result of the search step; and

a step of providing the referral target file existing in the storage destination that was determined at the determination step to the file referral requestor client.

10. The file management method of a storage system according to claim 9,

wherein the second server comprises:

a step of requesting the first server to process the referral target file among the files existing in the first memory device as a migration target file to become a migration target upon determining that the storage destination of the referral target file is the first memory device,

wherein the first server comprises;

a step of sending, in response to a request from the second server, the referral target file among the files existing in the first memory device as a migration target file to the second server, and

wherein the second server further comprises;

a step of providing the received migration target file as the referral target file to the file referral requestor client upon subsequently receiving the migration target file from the first server.

11. The file management method of a storage system according to claim 9,

wherein the second server comprises:

a step of requesting the first server to process the referral target file among the files existing in the first memory device as a migration target file to become the migration target upon determining that the storage destination of the referral target file is the first memory device,

wherein the first server comprises;

a step of acquiring the referral target file from the first memory device in response to the request from the second server; and

a step of sending the referral target file that was acquired at the acquisition step as the migration target file to the second server, and

wherein the second server further comprises;

a step of providing the received migration target file as the referral target file to the file referral requestor client upon receiving the migration target file from the first server; and

a step of storing the received migration target file in the second memory device.

12. The file management method of a storage system according to claim 11,

wherein the second server comprises:

a step of changing contents of a stub corresponding to the received migration target file to referral information showing access to the migration target file stored in the second memory device upon storing the received migration target file in the second memory device.

13. The file management method of a storage system according to claim 9,

wherein the first server comprises:

a step of sending, when the file input together with the file registration request becomes a migration target, a migration target file that became the migration target to the second server,

a step of creating a stub as referral information for accessing the migration target file of the migration destination based on metadata corresponding to the migration target file that was sent to the migration destination upon sending the migration target file to the second server as the migration destination; and

a step of storing the stub that was created at the creation step in the second memory device upon associating the created stub with metadata corresponding to the migration target file that was sent to the migration destination.

14. The file management method of a storage system according to claim 13,

wherein the first server comprises:

a step of searching the stub and the metadata stored in the first memory device according to the file referral request, determines a storage destination of a referral target file as a target of the file referral request based on the search result upon receiving a file referral request from the file referral requestor client; and

a step of determining a storage destination of a referral target file as a target of the file referral request based on the search result of the search step; and

a step of providing the referral target file existing in the storage destination that was determined at the determination step to the file referral requestor client.

15. The file management method of a storage system according to claim 14,

wherein the first server comprises:

a step of requesting the second server to process the referral target file among the files existing in the second memory device as the migration target file upon determining that the storage destination of the referral target file is the second memory device,

wherein the second server comprises;

a step of acquiring the referral target file from the second memory device in response to the request from the first server; and

a step of sending the referral target file that was acquired at the acquisition step as the migration target file to the first server, and

wherein the first server further comprises;

a step of providing the received migration target file as the referral target file to the file referral requestor client upon receiving the migration target file from the second server; and

a step of storing the received migration target file in the first memory device.