Method for accessing distributed file system

• US 20050267982A1
• Filed: 08/09/2005
• Published: 12/01/2005
• Est. Priority Date: 03/13/2003
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nakatani, Yoji, Iwasaki, Masaaki, Enko, Yutaka
• Granted Patent: US 7,284,041 B2
• Time in Patent Office: Days
• US Class Current: 709/233
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols

Abstract

In order to access a distributed file system (DFS) of the present invention using a conventional protocol such as the one for an NFS or a CIFS without making a modification on a client side, a gateway unit for receiving a conventional protocol and performing processing in conformity the protocol is provided for a DFS server. The gateway unit emulates a directory structure in a file system such as the NFS or CIFS. When the DFS is a write-once read-many file system, update processing is converted into processing for creating a new generation file, and reference processing is converted into access to a latest generation file in a generation-managed file group. The gateway unit then accesses a DFS file via a DFS processing unit.

Claims

1-23. -23. (canceled)

24. A gateway apparatus coupled to a client computer and a file server via a network, the gateway apparatus comprising:

a first unit, coupled to the network, which is configured to receive a first type file access request from the client computer and to respond to the received first type file access request based on a first type protocol;

a second unit, coupled to the first unit and the network, which is configured to issue a second type file access request to the file server based on a second type protocol; and

a directory management unit coupled to the first unit,

wherein the first type file access request includes a path name indicating a directory including a file to be accessed and a file name indicating the file, and the file name is a unique identifier in the directory,

wherein the second type file access request includes a file ID indicating the file in a second file system,

wherein the directory management unit manages information of relationship among path name information, file name information and file ID information,

wherein the first unit converts a first path name and a first file name included in the first type file access request to a first file ID corresponding to the first path name and the first file name in accordance with the information of relationship managed by the directory management unit, and sends the first file ID to the second unit,

wherein the second unit creates the second type file access request based on the first file ID sent by the first unit, and

wherein the first type file access request is converted into the second type file access request to be used by the second type file system to access to the file according to the second type protocol different from the first type protocol.

25. A gateway apparatus according to claim 24, wherein the first type file access request is based on a NFS protocol, a CIFS protocol, or both NFS and CIFS protocols.

26. A gateway apparatus according to claim 24, wherein the file ID is assigned to the file by the file server.

27. A gateway apparatus according to claim 24, wherein the file ID is modified by the file server.

28. A gateway apparatus according to claim 24, wherein the first unit registers information of a set of a new path name and a new file name of the a file included in the first type file access request into the directory management unit, directs the second unit to send the second type file access request which indicates to create a new file to the file server, gets a new file ID assigned to the new file by the file server, and registers information of the new file ID into the directory management unit in order to relate the new file ID to the set of the new path name and new file name of the new file if the first type file access request indicates to create the new file.

29. A gateway apparatus according to claim 24,

wherein the file ID includes a group identifier indicating a file group of the file and a generation identifier indicating a generation of updating the file,

wherein the file group includes the file and a plurality of files each of which has updated content of the file, and

wherein the plurality of files are distinguished from each other by using the generation identifier.

30. A gateway apparatus according to claim 24, wherein the first unit specifies a plurality of file IDs related to a second set of a second path name and a second file name of a second file included in the first type file access request, selects a second file ID including a last generation identifier in the plurality of file IDs, and directs the second unit to send the second type file access request which includes the second file ID to the file server if the first type file access request indicates to read content of the second file.

31. A gateway apparatus coupled to a client computer and a file server via a network, the gateway apparatus comprising:

an interface, coupled to the client computer and the file server via the network, which receives a first type file access request from the client computer based on a first type protocol and issues a second type file access request to the file server based on a second type protocol;

a processing unit coupled to the interface; and

a memory coupled to the processing unit,

wherein the first type file access request includes a path name indicating a directory including a file to be accessed and a file name indicating the file, and the file name is a unique identifier in the directory,

wherein the second type file access request includes a file ID indicating the file,

wherein the memory stores information of correspondence among path name information, file name information and file ID information, and

wherein the processing unit converts a set of a first path name and a first file name included in the first type file access request into a first file ID based on the information of correspondence stored in the memory, creates the second type file access request including the first file ID, and manages sending the second type file access request from the interface to the file server.

32. A gateway apparatus according to claim 31,

wherein the file ID indicates the file in a second file system, and

wherein the first type file access request is converted into the second type file access request to be used by the second type file system to access to the file according to the second type protocol different from the first type protocol.

33. A gateway apparatus according to claim 31, wherein the first type file access request is based on a NFS protocol, a CIFS protocol, or both NFS and CIFS protocols.

34. A gateway apparatus according to claim 31, wherein the file ID is assigned to the file by the file server.

35. A gateway apparatus according to claim 31, wherein the file ID is modified by the file server.

36. A gateway apparatus according to claim 31, herein, if the first type file access request indicates to create a new file, the processing unit registers information of a set of a new path name and a new file name of the new file included in the first type file access request into the memory, makes and sends the second type file access request which indicates to create the new file to the file server, gets a new file ID assigned to the new file by the file server, and registers information of the new file ID into the memory in order to relate the new file ID to the set of the new path name and new file name of the new file.

37. A gateway apparatus according to claim 31,

wherein the file ID includes a group identifier indicating a file group of the file and a generation identifier indicating a generation of updating the file,

wherein the file group includes the file and a plurality of files each of which has updated content of the file, and

wherein the plurality of files are distinguished each other by using the generation identifier.

38. A gateway apparatus according to claim 31, wherein, if the first type file access request indicates to read content of a second file, the processing unit specifies a plurality of file IDs related to a second set of a second path name and a second file name of the second file included in the first type file access request, selects a second file ID including a last generation identifier in the plurality of file IDs, and sends the second type file access request which includes the second file ID to the file server.