File sharing method and file sharing system

• US 20070250594A1
• Filed: 04/23/2007
• Published: 10/25/2007
• Est. Priority Date: 04/25/2006
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Ohtani, Atsuhisa
• Granted Patent: US 8,250,176 B2
• Time in Patent Office: Days
• US Class Current: 709/217
• CPC Class Codes: G06F 16/176 Support for shared access to files; File sharing support
• CPC Class Codes: G06F 16/188 Virtual file systems

Abstract

To perform rapid I/O processing for a large file reducing load on a server computer and a network.

The client computer accesses a disk device directly to perform input/output processing relating to a file operation through a channel switch based on real file information obtained by the client computer from a parent server computer upon a file-open operation. Further, a child server computer manages the disk device, which enables different real files in a same virtual file to be processed an I/O at the same time by a plurality of client computers.

Claims

1. A file sharing system comprising:

a child server computer for managing a plurality of disk devices;

a parent server computer for managing the child server computer; and

a plurality of client computers,

wherein

the disk devices store a large file divided,

the client computers, the child server computer, and the parent server computer are connected through a network, and

the plurality of disk devices, each of the client computers, and each of the child server computers are connected through a channel switch.

2. The file sharing system, as claimed in claim 1, wherein the parent server computer is provided with:

a child server managing unit for creating real file information which specifies a structure of a real file system in each of the disk device, a structure of a virtual file system over the real file systems, and a stored position of a real file in the virtual file system, and

a file management database for storing created real file information.

3. The file sharing system, as claimed in claim 1, wherein the client computer is provided with:

a real file information obtaining unit for sending a request to the parent server computer through the network so as to obtain real file information corresponding to a target file from the parent server computer upon a file-open operation, and

an I/O requesting unit for sending a request of inputting/outputting processing directly to a corresponding child server computer based on the obtained real file information so as to perform input/output processing relating to a file operation accessing directly the disk devices through the channel switch according to block I/O information sent by the child server computer.

4. The file sharing system, as claimed in claim 3, wherein the client computer is provided with:

a file management table for storing real file information, and

a real file information registering unit for registering the real file information obtained by the real file information obtaining unit in the file management table.

5. The file sharing system, as claimed in claim 3, wherein the I/O requesting unit comprising the functions of:

determining whether the real file information corresponding to the target file is stored or not in the file management table upon the file-open operation;

sending a request of input/output processing directly to the corresponding child server computer based on the real file information stored in the file management table in a case where it is stored; and

sending a request to the parent server computer through the network so as to obtain the real file information corresponding to the target file from the parent server computer in a case where it is not stored.

6. A file sharing method with which each child server computer managing a plurality of disk devices individually, a parent server computer managing the child server computer, and a plurality of client computers are connected communicably, and with which a large file is divided to be stored in the disk devices, the method comprising the steps of:

connecting the client computer, the child server computer and the parent server computer through a network, and the plurality of disk devices, the respective client computers, and the respective child server computers are connected through a channel switch; and

registering in advance real file information specifying a structure of a real file system in each of the disk devices, a structure of a virtual file system over the real file systems, and stored position of the real file in the virtual file system, into the parent server computer as file management database;

wherein

the client computer sends a request to the parent server computer through the network so as to obtain the real file information corresponding to a target file from the parent server computer upon the file-open operation, and

the client computer accesses directly the disk device through the channel switch so as to perform input/output processing relating to a file operation based on the real file information.

7. The file sharing method, as claimed in claim 6, wherein the client computer requests the parent server computer of the real file information of a real file continuing from the real file when the real file termination is detected in the disk device during the input/output processing relating to the file operation by the client computer to the disk device based on the real file information.

8. The file sharing method, as claimed in claim 6, wherein

the parent server computer creates a file handle of a directory in the virtual file system,

the parent server computer obtains a file handle of a file in the real file system from the child server computer based on an offset of a file in the virtual file system, and

the parent server computer sends the client computer the file handle of the directory in the virtual file system and the file handle of the file in the real file system as the real file information.

9. The file sharing method, as claimed in claim 6, wherein the client computer comprising the functions of:

storing the real file information obtained from the parent server computer in a file management table; and

determining whether or not the real file information corresponding to the target file is stored in the file management table upon the file-open operation;

the method further comprising the functions of;

starting the input/output processing relating to the file operation sending a request for the input/output processing directly to the child server computer based on the real file information stored in the file management table if it is stored; and

obtaining the real file information corresponding to the target file from the parent server computer sending a request to the parent server computer through the network if it is not stored.