STORAGE MANAGEMENT DEVICE, STORAGE SYSTEM CONTROL DEVICE, STORAGE MEDIUM STORING STORAGE MANAGEMENT PROGRAM, AND STORAGE SYSTEM

• US 20090150629A1
• Filed: 11/11/2008
• Published: 06/11/2009
• Est. Priority Date: 12/05/2007
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Take, Riichiro, Watanabe, Takashi, Ogihara, Kazutaka, Noguchi, Yasuo, Tsuchiya, Yoshihiro, Maruyama, Tetsutaro, Tamura, Masahisa, Kumano, Tatsuo
• Granted Patent: US 8,234,467 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1402 Saving, restoring, recovering or retrying
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality

Abstract

A storage management device includes a management unit for managing a storage device assigned thereto and a temporary storage unit assigned thereto. The management unit comprises a backup unit for, when data is written into the storage device, storing the data in the previously assigned temporary storage unit before the writing of the data into the storage device is completed, and a take-over unit for, when data which is already stored in the temporary storage unit, but which is not yet written into the storage device exists when the storage device and the temporary storage unit are assigned, writing the not-yet-written data into the storage device.

Claims

1. A storage management device used in a storage system, which stores data in a plurality of storage devices interconnected via a network in a distributed manner, for managing the storage device, the storage management device comprising:

management unit managing one of the storage devices assigned thereto and temporary storage unit assigned thereto,

the management unit comprising;

backup unit, when the data is written into the storage device, storing the data in the previously assigned temporary storage unit before the writing of the data into the storage device is completed; and

take-over unit, when data which is already stored in the temporary storage unit, but which is not yet written into the storage device exists at timing the storage device and the temporary storage unit are assigned, writing the not-yet-written data into the storage device.

2. The storage management device according to claim 1, wherein the storage device and the temporary storage unit are assigned by a storage system control device for controlling the storage system by managing the storage management device, and

wherein when the data which is already stored in the temporary storage unit, but which is not yet written into the storage device exists at timing the storage device and the temporary storage unit are assigned by the storage system control device, the take-over unit writes the not-yet-written data into the storage device.

3. The storage management device according to claim 2, wherein after the writing of the data into the storage device has been completed, the backup unit erases the data having been written into the temporary storage unit.

4. The storage management device according to claim 2, wherein when the data which is already stored in the temporary storage unit, but which is not yet written into the storage device exists at timing the storage device and the temporary storage unit are assigned, the take-over unit reads the not-yet-written data from the temporary storage unit and writes the not-yet-written data into the storage device.

5. The storage management device according to claim 2, further comprising internal storage unit for storing data not yet completely written when the data is written into the storage device,

wherein the backup unit stores the not-yet-written data in the internal storage unit before the writing of the data into the storage device is completed, and

wherein when data which is already stored in the internal storage unit, but which is not yet written into the storage device exists at timing the temporary storage unit is assigned, the take-over unit reads the data from the internal storage unit and writes the not-yet-written data into the storage device.

6. The storage management device according to claim 5, wherein after the writing of the data into the storage device has been completed, the backup unit erases the data having been written into the internal storage unit.

7. The storage management device according to claim 2, wherein, after the data writing into the temporary storage unit has been completed, but before the data writing into the storage unit has been completed, the backup unit outputs a write completion response notifying that the data writing into the temporary storage unit has been completed.

8. The storage management device according to claim 2, wherein, in accordance with an instruction from the storage system control device, the backup unit is able to, when the data is written into the storage device, selectively change between an ordinary mode in which the data is stored in the assigned temporary storage unit before completion of the data writing into the storage device, and a synchronous mode in which the data is written into the storage device without storing the data in the temporary storage unit.

9. The storage management device according to claim 2, wherein the storage management device includes the temporary storage unit therein.

10. The storage management device according to claim 9, wherein the temporary storage unit is assigned to the storage management device other than the storage management device which includes the temporary storage unit therein.

11. A storage system control device for controlling a storage system which stores data in a plurality of storage devices,

the storage system control device controlling the storage system by managing a storage management device which is capable of managing the storage device and capable of, when the data is written into the storage device, storing the data in a previously assigned temporary storage unit before the writing of the data into the storage device is completed,

the storage system control device comprising;

failure detection unit for detecting a failure of the storage management device; and

assignment unit for assigning the storage device and the temporary storage unit to the storage management device,

wherein when the failure of the storage management device is detected by the failure detection unit, the assignment unit assigns, to another storage management device, the storage device and the temporary storage unit, which have been assigned to the storage management device causing the failure detected by the failure detection failure.

12. The storage system control device according to claim 11, wherein the failure detection unit further detects a failure of the temporary storage unit, and

wherein when the failure of the temporary storage unit is detected by the failure detection unit, the assignment unit assigns another temporary storage unit to the storage management device to which the temporary storage unit causing the failure detected by the failure detection failure has been assigned.

13. The storage system control device according to claim 11, wherein the temporary storage unit is included in the storage management device, and

wherein when the temporary storage unit included in the storage management device is assigned to one storage management device including one temporary storage unit, the assignment unit assigns, to the one storage management device, the temporary storage unit included in the storage management device other than the one storage management device.

14. A recording medium storing a storage management program causing a computer to execute, in a storage system which stores data in a plurality of storage devices interconnected via a network in a distributed manner, a process of managing the storage device, the program causing:

the computer to function as management unit for managing one of the storage devices assigned thereto and temporary storage unit assigned thereto, and

the management unit to function as;

backup unit, when the data is written into the storage device, storing the data in the previously assigned temporary storage unit before the writing of the data into the storage device is completed; and

take-over unit, when data which is already stored in the temporary storage unit, but which is not yet written into the storage device exists at timing the storage device and the temporary storage means are assigned, writing the not-yet-written data into the storage device.

15. A storage system for storing data in a plurality of storage devices interconnected via a network in a distributed manner, the storage system comprising:

a storage management device including management means for managing one of the storage devices assigned thereto and temporary storage unit assigned thereto; and

a storage system control device for controlling the storage system by managing the storage management device,

the storage system control device including assignment unit for assigning the storage device and the temporary storage unit to the storage management device,

the management means comprising;

backup unit for, when the data is written into the storage device, storing the data in the previously assigned temporary storage unit before the writing of the data into the storage device is completed; and

take-over unit for, when data which is already stored in the temporary storage unit, but which is not yet written into the storage device exists at timing the storage device and the temporary storage unit are assigned, writing the not-yet-written data into the storage device.