Storage system, method for processing, and program

• US 20060190682A1
• Filed: 05/27/2005
• Published: 08/24/2006
• Est. Priority Date: 02/18/2005
• Status: Abandoned Application

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Take, Riichiro, Ogihara, Kazutaka, Noguchi, Yasuo, Toda, Seiji, Ohta, Mitsuhiko
• Application Number:
  US11/138,267
• Publication Number:
  US 20060190682A1
• Time in Patent Office: Days
• US Class Current: 711/114
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G06F 11/2082 Data synchronisation
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores

Abstract

In a storage system, a plurality of RAID devices are connected to a network, and data is multiplexed to primary data and secondary data by being mirrored among the RAID devices. When a failure of a disk device that can be recovered within the devices owing to the RAID configuration occurs, data of a disk device corresponding to the failed disk device is requested to a RAID device that is its mirror target and the transferred data is written to a spare disk device for the recovery. At the time of the data recovery, an access right to a group of disk devices constituting RAID and an access right to individual disk devices are exclusively controlled with respect to an input and output of the primary data.

Claims

1. A storage system in which a plurality of RAID devices are connected to a network and data is multiplexed to primary data and secondary data by being mirrored among the RAID devices, each of the RAID devices of the storage system comprising:

a plurality of devices provided with devices constituting RAID and a spare device;

a RAID processing unit that executes request processing targeting for the device constituting RAID that store primary data for a request from a host device;

a copy request processing unit that requests data of a device corresponding to a failed device to a RAID device that is its mirror target at the time of occurrence of a device failure that can be recovered within the devices owing to the RAID configuration and writes the transferred data to the spare device for the recovery;

a copy response processing unit that reads out the data of the target device and transfers it to the requesting source upon receiving the data request from the RAID device that has the failure; and

an exclusion mechanism that exclusively controls an access right to the devices constituting RAID and an access right to individual devices.

2. The storage system according to claim 1, wherein when the failed device stores primary data, the copy request processing unit requests its secondary data to a RAID device that is its mirror target, writes the transferred secondary data to a spare device for the recovery, and

when the secondary data request is received from the RAID device that has the failure, the copy response processing unit reads out the secondary data of the target device and transfers it to the requesting source.

3. The storage system according to claim 2, wherein the exclusion mechanism acquires an exclusive access right to the spare device prior to the secondary data request by the copy request processing unit and releases the exclusive access right after the transferred secondary data is written to the spare device.

4. The storage system according to claim 1, wherein when the failed device stores secondary data, the copy request processing unit requests its primary data to a RAID device that is its mirror target, writes the transferred primary data to a spare device for the recovery, and then posts the completion of write, and

When the primary data request is received from the RAID device that has the failure, the copy response processing unit reads out the primary data of the target device and transfers it to the requesting source.

5. The storage system according to claim 4, wherein when the copy response processing unit receives the primary data request from the RAID device that has the failure, the exclusion mechanism acquires an exclusive access right to the target device for access, allows the primary data to be read out and transferred, and after the transfer, receives a notice of the completion of write from the RAID device that has the failure to release the exclusive access right.

6. The storage system according to claim 1, wherein the RAID device retains mirror configuration information that shows a RAID device that is a mirror target and RAID configuration information that shows devices constituting RAID, and

the copy request processing unit not only searches a RAID device that serves as a mirror target from the mirror configuration information but also searches a device corresponding to the failed device from the RAID configuration information to request the data at the time of a device failure.

7. The storage system according to claim 1, wherein data is multiplexed by being mirrored in all of the RAID devices.

8. The storage system according to claim 1, wherein data is multiplexed by changing a mirror target for every management unit of the RAID device.

9. The storage system according to claim 1, wherein the RAID device is connected under each of nodes that are configured with a cluster of computers connected to the network.

10. A method for processing of storage system in which a plurality of RAID devices are connected to a network and data is multiplexed to primary data and secondary data by being mirrored among the RAID devices, the method for processing of storage system comprising steps of:

RAID processing that executes request processing targeting for devices constituting RAID of a plurality of devices that store primary data for a request from a host device;

copy request processing that requests data of a device corresponding to a failed device to a RAID device that is its mirror target at the time of occurrence of a device failure that can be recovered within the devices owing to the RAID configuration and writes the transferred data to a spare device for the recovery;

copy response processing that reads out the data of the target device and transfers it to the requesting source upon receiving the data request from the RAID device that has the failure; and

exclusive control that exclusively controls an access right to the devices constituting RAID and an access right to individual devices.

11. The method according to claim 10, wherein at the copy request processing step, secondary data is requested to a RAID device that is a mirror target when the failed device stores its primary data and the transferred secondary data is written to a spare device for the recovery;

and

at the copy response processing step, the secondary data of the target device is read out and transferred to the requesting source when the secondary data request is received from the RAID device that has the failure.

12. The method according to claim 11, wherein at the exclusive control step, an exclusive access right to the spare device is acquired prior to the secondary data request at the copy request processing step, and after the transferred secondary data is written to the spare device, the exclusive access right is released.

13. The method according claim 10, wherein at the copy request processing step, primary data is requested to a RAID device that is a mirror target when the failed device stores its secondary data, the transferred primary data is written to a spare device for the recovery, and then the write completion is posted;

and

at the copy response processing step, the primary data is read out from the target device and transferred to the requesting source when the primary data request is received from the RAID device that has the failure.

14. The method according to claim 13, wherein at the exclusive control step, an exclusive access right to the target device for access is acquired when the primary data request is received from the RAID device that has the failure at the copy response processing step, the primary data is allowed to be read out and transferred, and after the transfer, the exclusive access right is released when a notice of the write completion is received from the RAID device that has the failure.

15. The method according to claim 10, wherein the RAID device retains mirror configuration information showing a RAID device that is a mirror target and RAID configuration information showing devices constituting RAID;

and

at the copy request processing step, not only is a RAID device that is a mirror target searched from the mirror configuration information but also a device corresponding to the failed device is searched from the RAID configuration information for requesting data.

16. The method according to claim 10, wherein data is multiplexed by being mirrored in all of the RAID devices.

17. The method according to claim 10, wherein data is multiplexed by changing a mirror target for every management unit in the RAID device.

18. The method according to claim 10, wherein the RAID device is connected under each of nodes of a cluster of computers connected to the network.

19. A program for processing storage system, which a plurality of RAID devices are connected to a network, that allow data to be multiplexed to primary data and secondary data by mirroring among the RAID devices, wherein said program allows a computer to execute:

RAID processing that executes request processing targeting for devices constituting RAID of a plurality of devices that store primary data for a request from a host device;

copy request processing that requests data of a device corresponding to a failed device to a RAID device that is its mirror target at the time of occurrence of a device failure that can be recovered within the devices owing to the RAID configuration occurs and writes the transferred data to a spare device for the recovery;

copy response processing that reads out the data of the target device and transfers it to the requesting source upon receiving the data request from the RAID device that has the failure; and

exclusive control that exclusively controls an access right to the devices constituting RAID and an access right to individual devices.

20. The program according to claim 19, wherein at the copy request processing step, secondary data is requested to a RAID device that is a mirror target when the failed device stores its primary data and the transferred secondary data is written to a spare device for the recovery;

and

at the copy response processing, the secondary data of the target device is read out and transferred to the requesting source when the secondary data request is received from the RAID device that has the failure.