File-sharing system and method of using file-sharing system to generate single logical directory structure

• US 20080320051A1
• Filed: 01/11/2008
• Published: 12/25/2008
• Est. Priority Date: 06/19/2007
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Murotani, Akira, Higaki, Seiichi
• Granted Patent: US 7,987,206 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/1827 Management specifically adapted to NAS management of storage area networks [SAN] G06F3/067

Abstract

The file sharing system of the present invention is able to provide a client with a single logical directory and reproduces the single logical directory in a remote site when the local site has stopped in use of a remote copy that is made between the local site and remote site. The first site provides the client with a logical directory that is constituted across respective nodes in the first site. The remote copy is executed between the first and second sites, and the data of both sites are synchronized. For the generation of the logical directory and the management of the remote copy, a common management table is used, and the management table is held by all of the nodes. In cases where the first site stops due to a fault, the second site utilizes information related to the remote copy in the management table to construct the logical directory and reproduces the logical directory in the second site.

Claims

1. A file sharing system having a first site and a second site, wherein

a plurality of first file sharing devices in the first site and a plurality of second file sharing devices in the second site are connected to enable mutual communication via a first communication path capable of data communication in file units,

the system comprising:

a logical directory supply section which, by using first management information for managing associated relationship between a single logical directory structure that is generated across the respective first file sharing devices and a first directory structure that the respective first file sharing devices comprise, supplies the logical directory structure that is formed by virtually integrating the respective first directory structures to a client device;

a copy control section which, by using second management information for managing associated relationship between storage positions of data managed by the respective first file sharing devices and storage positions of data managed by the respective second file sharing devices, transmits and copies copy target data among the data stored in the respective first file sharing devices to second file sharing devices that are associated with the respective first file sharing devices; and

a reproduction section which reproduces the logical directory structure that is formed by virtually integrating the respective second directory structure by using the first management information and the second management information in cases where a fault occurs at the first site.

2. The file sharing system according to claim 1, wherein the structure of the volume used by the respective first file sharing devices to input and output data and the structure of the volume used by the respective second file sharing devices to input and output data are different.

3. The file sharing system according to claim 1, wherein

the first management information includes respective directory names of the logical directory structures, responsibility information for specifying predetermined first file sharing devices that are responsible for the respective directory names;

and first storage position information for indicating the storage position of the data managed by the predetermined respective first file sharing devices; and

the second management information includes the first storage position information, second storage position information for indicating the storage position of data managed by the respective second file sharing devices, and copy destination device information for specifying second file sharing devices that are associated with the predetermined first file sharing devices.

4. The file sharing system according to claim 1, wherein

the first management information and the second management information are stored in a common management table;

the management table is constituted comprising respective directory names of the logical directory structures, responsibility information for specifying predetermined first file sharing devices that are each responsible for the respective directory names, first storage position information indicating the storage position of data managed by the respective predetermined first file sharing devices, copy destination device information for specifying predetermined second file sharing devices that each correspond with the respective predetermined first file sharing devices, and second storage position information indicating the storage positions of data managed by the respective second file sharing devices, and wherein

the reproduction section reproduces the logical directory structures by treating the copy destination device information as the responsibility information in cases where a fault has occurred.

5. The file sharing system according to claim 1, wherein the copy control section transmits and copies the copy target data from the first file sharing devices to the second file sharing devices via the first communication path.

6. The file sharing system according to claim 1, wherein

the respective first file sharing devices store and manage data in a first volume provided by a first storage device in the first site;

the respective second file sharing devices store and manage data in a second volume provided by a second storage device in the second site;

the first storage device and the second storage device are connected to enable mutual communication via a second communication path that is capable of data communication in block units; and

the copy control section transfers and copies the copy target data from the first volume to the second volume via the second communication path.

7. The file sharing system according to claim 6, wherein

the second volume stores copy source volume identification information for identifying the first volume associated as the copy source with the second volume;

and

the reproduction section reproduces the logical directory structure that is formed by virtually integrating the respective second directory structure by using the copy source volume identification information, the first management information, and the second management information.

8. The file sharing system according to claim 1, wherein

the respective first file sharing devices and the respective second file sharing devices hold the first management information and the second management information, and

in cases where either the first site or the second site undergoes a change to the logical directory structure or a copy-related structure, differential information related to the structural change is reported to the respective first file sharing devices and the respective second file sharing devices, and the differential information is reflected in the first management information or the second management information held by the respective first file sharing devices and the respective second file sharing devices.

9. A method of generating a single logical directory structure by using a file sharing system, the file sharing system having a first site having a plurality of first file sharing devices, a second site having a plurality of second file sharing devices, and a first communication path that is connected such that the respective first file sharing devices and the respective second file sharing devices are able to perform data communication in file units,

the method comprising the steps of:

setting first management information for managing associated relationship between a single logical directory structure which is generated across the respective first file sharing devices and a first directory structure that the respective first file sharing devices comprise;

providing a client device with a logical directory structure that is made by using the first management information to virtually integrate the respective first directory structures;

setting second management information for managing associated relationship between storage positions of data managed by the respective first file sharing devices and storage positions of data managed by the respective second file sharing devices;

transmitting and copying copy target data among the data that are stored in the respective first file sharing devices to second file sharing devices that are associated with the respective first file sharing devices by using the second management information;

detecting whether a fault has occurred in the first site; and

reproducing the logical directory structure that is formed by virtually integrating the respective second directory structure by using the first management information and the second management information in cases where the occurrence of a fault is detected.

10. A file sharing system having a first site and a second site, wherein

(1) the first site comprises:

(1-1) a plurality of first file sharing devices each having a first directory structure;

(1-2) a first storage device which is connected via a first intra-site communication network to the respective first file sharing devices, and which supplies a first volume to the first file sharing devices respectively; and

(1-3) a master device that issues a predetermined report to the first file sharing devices respectively; and

(2) the second site comprises;

(2-1) a plurality of second file sharing devices each having a second directory structure and being provided in a number that differs from the number of first file sharing devices;

(2-2) a second storage device which is connected via a second intra-site communication network to the respective second file sharing devices and which supplies a second volume to the second file sharing devices respectively; and

(2-3) a submaster device that issues a predetermined report to the second file sharing devices respectively;

(3) the respective first file sharing devices and the respective second file sharing devices are connected via a first communication path that is capable of data communication in file units, and the first storage device and the second storage device are connected via a second communication path that is capable of data communication in block units;

(4) the respective first file sharing devices, the respective second file sharing devices, the master device, and the submaster device each hold a management table, and the management table is constituted comprising respective directory names that correspond to respective node names of the logical directory structure, responsibility information for specifying predetermined first file sharing devices responsible for each of the directory names, first storage position information indicating storage positions of data managed by the respective predetermined first file sharing devices, copy destination device information for specifying predetermined second file sharing devices each corresponding to the respective predetermined first file sharing devices, and second storage position information indicating storage positions of data managed by the respective predetermined second file sharing devices;

(5) the master device generates a single logical directory structure that is generated across the respective first file sharing devices by using the management table and supplies the single logical directory structure to a client device;

(6) the respective first file sharing devices transmit data that are stored in the first volume to the respective second file sharing devices via the first communication path by using the management table and store the data in the second volume; and

(7) the submaster device reproduces the logical directory structure by means of a second directory structure that the respective second file sharing devices comprise by treating the copy destination device information in the management table as the responsibility information in cases where execution of a failover is instructed.