System and method for virtualizing network storages into a single file system view

• US 20040010654A1
• Filed: 03/14/2003
• Published: 01/15/2004
• Est. Priority Date: 07/15/2002
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Higuchi, Tatsuo, Okitsu, Jun, Kawamoto, Shinichi, Yasuda, Yoshiko, Ebata, Atsushi
• Granted Patent: US 7,587,471 B2
• Time in Patent Office: Days
• US Class Current: 711/1
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

A system and method for virtualizing a new network storage additionally installed and an existing network storage as a single file system by inheriting a directories tree structure from the existing network storage, wherein a virtualizing system of the new network storage has the function of reading out setup information of the existing network storage according to an expansion request from the administrator, registering the existing network storage as a member of the virtualizing system, copying a directories tree structure of the existing network storage, and swapping setup information of the existing network storage and that of he new network storage with each other.

Claims

1. A virtualizing method for constructing a virtualized-and-unified file system for allowing a client connected to a network to access a virtualized network storage instead of at least two old and new network storages distributed on the network, comprising the steps of:

reading out basic setup information including name information and identification information of the old network storage from said old network storage;

registering the identification information of said old network storage as member information of said virtualized-and-unified file system; and

copying a files-and-directories tree structure of said old network storage into said virtualized-and-unified file system by using said member information and the basic setup information of said old network storage,

wherein said virtualized-and-unified file system inherits the files-and-directories tree structure from said old network storage.

2. The virtualizing method according to claim 1, wherein said basic setup information further includes an IP address and a mount point of said old network storage.

3. The virtualizing method according to claim 1, further comprising the steps of:

registering said new network storage as a member of said virtualized-and-unified file system; and

swapping the basic setup information of said old network storage and the basic setup information of said new network storage with each other,

wherein said old network storage is replaced with said new network storage.

4. The virtualizing method according to claim 3, further comprising a step of migrating a file existing in said old network storage to said new network storage.

5. The virtualizing method according to claim 4, further comprising the steps of:

correlating each of files with one of said old and new network storages holding the file;

receiving a file-access request designating one of said files from said client;

specifying a network storage holding the file designated by said file-access request in accordance with said correlation; and

transferring the file-access request to the specified network storage.

6. The virtualizing method according to claim 4, wherein the step of moving a file in said old network storage to the new network storage is executed without stopping file access requests from said client.

7. The virtualizing method according to claim 4, further comprising the steps of:

correlating each of files with a file group to which the file belongs;

correlating a file group with one of said old and new network storages to which the file group belongs;

receiving a file-access request designating one of said files from said client by said virtualized-and-unified file system;

specifying a file group to which the file designated by the file access request belongs and a network storage to which the file group belongs, in accordance with said correlation association by said virtualized-and-unified file system; and

issuing a file access request to the specified network storage holding the designated file.

8. The virtualizing method according to claim 7, wherein a file group to which said designated file belongs is determined according to identification information of the file.

9. A virtualizing apparatus for constructing a virtualized-and-unified file system for allowing a client connected to a network to access a virtualized network storage instead of at least two old and new network storages distributed on the network, comprising:

a host table for holding member information of said virtualized-and-unified file system;

means for reading out basic setup information including name information of a storage from said old network storage;

means for registering the name information of said old network storage into the host table; and

means for copying a files-and-directories tree structure of said old network storage into said virtualized-and-unified file system by using said host table and the basic setup information,

wherein said virtualized-and-unified file system inherits the files-and-directories tree structure from said old network storage.

10. The virtualizing apparatus according to claim 9, further comprising:

means for registering name information of said new network storage into the host table; and

means for swapping the basic setup information of said old network storage and the basic setup information of said new network storage with each other,

wherein said new network storage stands for said old network storage to said client.

11. The virtualizing apparatus according to claim 10, further comprising means for moving a file from said old network storage to said new network storage.

12. The virtualizing apparatus according to claim 11, further comprising:

request processing means for processing a file access request from said client; and

mapping means for determining a network storage in which a new file is to be located when the new file is created by said request processing means,

wherein when a request for accessing a file is received from said client, the received request is transferred to a network storage-determined by said mapping means.

13. The virtualizing apparatus according to claim 9, wherein member information stored in said host table includes name information and a mount point of said network storage, and an identifier of a network storage, which is unified in said virtualized-and-unified file systems.

14. The virtualizing apparatus according to claim 9, wherein the virtualizing apparatus is mounted on a new network storage.

15. The virtualizing apparatus according to claim 11, further comprising:

request processing means for processing a file access request from said client; and

mapping means for determining a network storage in which a new file is to be disposed when the new file is created by said request processing means,

the mapping means comprising;

means for determining, on the basis of identification information of a file, a file group to which the file belong; and

means for determining, on the basis of the file group to which said file belongs,;

a network storage to which the file group belongs,

wherein when a request for accessing a file is issued from said client, the received request is transferred to a network storage determined by said mapping means.

16. A virtualizing method for constructing a virtualized-and-unified file system for allowing a client connected to a network to access a virtualized network storage instead of at least two old and new network storages distributed on the network, comprising the steps of:

setting basic setup information including an IP address and name information of the new network storage from said client to said new network storage via said network;

a step of setting a command for capacity expansion or replacement and name information of said old network storage to be expanded its capacity or replaced, into said new network storage via said network from said client; and

a step of dynamically constructing a virtualized-and-unified file system by said new network storage, when said command and the name information of the old network storage are received from said client, by accessing said old network storage and inheriting a files-and-directories tree structure from said old network storage.

17. The virtualizing method according to claim 16, wherein said client sets information for discriminating whether said old network storage is virtualized or not, together with said command and name information of the old network storage to said new network storage.

18. An expansion processing method for expanding capacity of an old network storage connected to a network by connecting a new network storage having a virtualizing system to the network, comprising the steps of:

reading out setup information from said old network storage;

registering said old network storage as a member to said virtualizing system;

copying a files-and-directories tree structure of said old network storage to said new network storage;

registering said new network storage as a member to said virtualizing system; and

swapping setup information of said old network storage and that of said new network storage with each other.