Storage system, NAS server and snapshot acquisition method

• US 20070136391A1
• Filed: 02/08/2006
• Published: 06/14/2007
• Est. Priority Date: 12/09/2005
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nakatani, Yoji, Nakano, Takahiro, Anzai, Tomoya
• Granted Patent: US 7,885,930 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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

The correspondence relationship between local paths in local namespaces for snapshots FS0-SNAP0, FS1-SNAP0, and FS2-SNAP0 of file systems FS0, FS1, and FS2 and global paths in a global namespace for those snapshots is defined so that the directory configuration in the global namespace of the snapshots FS0-SNAP0, FS1-SNAP0, and FS2-SNAP0 becomes the same as the directory configuration in the global namespace of the file systems FS0, FS1, and FS2.

Claims

1. A storage system comprising:

a storage device for storing a file;

one or more file systems for managing the file; and

one or more NAS servers that control access from a client to the file systems via a global namespace formed by grouping local namespaces for the one or more file systems;

wherein each NAS server includes a global snapshot construction means for reconstructing the global namespace so that the directory configuration in the global namespace of the snapshot of the file system obtained by its own or other NAS servers becomes the same as the directory configuration in the global namespace of the file system.

2. The storage system according to claim 1, wherein the NAS server further includes a snapshot acquisition instruction means for instructing its own or other NAS servers to obtain a snapshot of the file system,

wherein the global snapshot construction means reconstructs the global namespace so that the directory configuration in the global namespace of the snapshot obtained according to the instruction becomes the same as the directory configuration in the global namespace of the file system.

3. The storage system according to claim 2, wherein the NAS servers operate synchronously with each other, any one of the one or more NAS servers instructs other NAS servers to obtain a snapshot of the file system according to a predetermined schedule, and reconstructs the global namespace so that the directory configuration in the global namespace of each snapshot obtained according to the instruction becomes the same as the directory configuration in the global namespace of the file system.

4. A storage system comprising:

a storage device for storing a file;

one or more file systems for managing the file;

one or more NAS servers that control access from a client to the file systems via a global namespace formed by grouping local namespaces of the one or more file systems; and

a computer connected to the NAS server,

wherein the computer includes global snapshot construction means that reconstructs the global namespace so that the directory configuration in the global namespace of the snapshot of the file system obtained by the NAS server becomes the same as the directory configuration in the global namespace of the file system.

5. The storage system according to claim 4, wherein the computer further includes a snapshot acquisition instruction means for instructing the NAS server to obtain a snapshot of the file system,

wherein the global snapshot construction means reconstructs the global namespace so that the directory configuration in the global namespace of each snapshot obtained according to the instruction becomes the same as the directory configuration in the global namespace of the file system.

6. The storage system according to claim 5, wherein the NAS servers operate synchronously with each other, each NAS server obtains a snapshot of the file system according to a predetermined schedule and notifies the computer of the local path for the obtained snapshot, and the computer reconstructs the global namespace so that the directory configuration in the global namespace of the snapshot becomes the same as the directory configuration in the global namespace of the file system.

7. A storage system comprising:

a storage device for storing a file,

one or more file systems for managing the file; and

one or more NAS servers that control access from a client to the file systems via a single namespace by linking a local path in each local namespace for the one or more file systems with a global path in the single namespace,

wherein the NAS server includes a global snapshot construction means for defining a correspondence relationship between the local path in the local namespace for the snapshot and the global path in the single namespace for the snapshot so that the directory configuration of the single namespace of the snapshot of the file system obtained by its own or other NAS servers becomes the same as the directory configuration in the single namespace of the file system.

8. A storage system comprising:

a storage device for storing a file;

one or more file systems for managing the file;

one or more NAS servers that control access from a client to the file systems via a single namespace by linking a local path in each local namespace for the one or more file systems with a global path in the single namespace; and

a computer connected to the NAS server,

wherein the computer includes a global snapshot construction means for defining a correspondence relationship between the local path in the local namespace for the snapshot and the global path in the single namespace for the snapshot so that the directory configuration in the single namespace of the snapshot of the file system obtained by the NAS server becomes the same as the directory configuration in the single namespace of the file system.

9. A NAS server that controls access from a client to one or more file systems via a global namespace formed by grouping local namespaces of the file systems, the NAS server comprising:

a global snapshot construction means for reconstructing the global namespace so that the directory configuration in the global namespace of a snapshot of the file system obtained by its own or other NAS servers becomes the same as the directory configuration in the global namespace of the file system.

10. The NAS server according to claim 9, further comprising a snapshot acquisition instruction means for instructing its own or other NAS servers to obtain the snapshot of the file system,

wherein the global snapshot construction means reconstructs the global namespace so that the directory configuration in the global namespace of each snapshot obtained according to the instruction becomes the same as the directory configuration in the global namespace of the file system.

11. The NAS server according to claim 10, which operates synchronously with the other NAS servers instructs other NAS servers to obtain a snapshot of the file system according to a predetermined schedule, and reconstructs the global namespace so that the directory configuration in the global namespace of each snapshot obtained according to the instruction becomes the same as the directory configuration in the global namespace of the file system.

12. A NAS server that controls access from a client to one or more file systems via a single namespace by linking a local path in each local namespace for the file systems with a global path in the single namespace, the NAS server comprising:

a global snapshot construction means for defining a correspondence relationship between the local path in the local namespace for the snapshot and the global path in the single namespace of the snapshot so that a directory configuration in the single namespace of the snapshot of the file system obtained by its own or other NAS servers becomes the same as the directory configuration in the single namespace of the file system.

13. A snapshot acquisition method comprising the steps of:

providing a client with a global namespace formed by grouping local namespaces of one or more file systems that manage a file stored in a storage device;

acquiring a snapshot of the file system; and

reconstructing the global namespace so that the directory configuration in the global namespace of the snapshot of the file system becomes the same as the directory configuration in the global namespace of the file system.

14. The snapshot acquisition method according to claim 13, wherein the step of acquiring the snapshot is a step of acquiring the snapshot of the file system according to a predetermined schedule.

15. A snapshot acquisition method comprising the steps of:

providing a client with a single namespace by linking a local path in each local namespace for one or more file systems with a global path in a single namespace;

acquiring a snapshot of the file system; and

defining a correspondence relationship between the local path in the local namespace of the snapshot and the global path in the single namespace of the snapshot so that the directory configuration in the single namespace of the snapshot of the file system becomes the same as the directory configuration in the single namespace of the file system.