Storage control system and storage control method

• US 20060248297A1
• Filed: 06/30/2005
• Published: 11/02/2006
• Est. Priority Date: 05/02/2005
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamagami, Kenji, Watanabe, Haruaki
• Granted Patent: US 7,660,946 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 12/0871 Allocation or management of cache space
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

Provided is a storage control system in which a number of storage controllers are connected, and restored data is forwarded from one storage controller to the other storage controller. With this storage control system, even when the host system accesses the logical volume of the forwarding destination of the restored data, the host system will be able to reliably access the restored data. This storage control system is configured by a first storage controller and a second storage controller being connected in a mutually communicable manner, and which performs data processing according to a request from a host system, the first storage controller having a virtual volume associated with a logical volume of the second storage controller; a cache memory associated with the virtual volume; and a control unit for controlling the data processing between the cache memory and the virtual volume; wherein the control unit purges the storage area of the cache memory corresponding to the virtual volume accessed by the host system upon storing the restored data of the logical volume in the cache memory.

Claims

1. A storage control system configured by a first storage controller and a second storage controller being connected in a mutually communicable manner, and which performs data processing according to a request from a host system,

said first storage controller comprising:

a virtual volume associated with a logical volume of said second storage controller;

a cache memory associated with said virtual volume; and

a control unit for controlling the data processing between said cache memory and said virtual volume;

wherein said control unit purges the storage area of said cache memory corresponding to said virtual volume accessed by said host system upon storing restored data of said logical volume in said cache memory.

8. The storage control system according to claim 1, wherein the control unit of said second controller starts said restoration after the control unit of said first storage controller completes the purge.

9. The storage control system according to claim 1, wherein said virtual volume comprises a directory configuration set with information for controlling the correspondence with the storage area of the cache memory of said first storage controller, said directory configuration comprises a plurality of management areas, and information for specifying the storage area of the cache memory of said first storage controller corresponding to the management area is set in each management area.

10. The storage control system according to claim 9, wherein each of said management areas comprises information for controlling the validity or invalidity of the stored data of said cache memory storage area.

11. The storage control system according to claim 1,

wherein the control unit of said first storage controller purges said specific information of the overall management area of said virtual volume, and subsequently assigns the data stored in the logical volume of said second storage controller to the cache memory of said first storage controller so as to enable said host system to access said data.

12. The storage control system according to claim 1,

wherein the control unit of said first storage controller purges said specific information of certain management areas of said virtual volume, and subsequently assigns the data stored in the logical volume of said second storage controller to the cache memory of said first storage controller so as to enable said host system to access said data.

13. The storage control system according to claim 12, wherein the control unit of said first storage controller sets an overall generation number to said virtual volume and sets individual generation numbers to each management area of said virtual volume, compares the generation number of the management area of said volume accessed by said host system and said overall number, and determines the data of the storage area of the cache memory corresponding to said management area to be said restored data when both numbers coincide, and purges the data of the storage area of the cache memory corresponding to said management area when both numbers do not coincide, and subsequently stores said restored data in said storage area.

14. The storage control system according to claim 13, wherein the control unit of said first storage controller renews the representative generation number of said virtual volume each time it receives said purge command from said host system.

17. The storage control system according to claim 9, wherein said purge processing is for the control unit of said first storage controller to set a control code indicating to the management area of said virtual volume that there is no correspondence with the storage area of said cache memory.

19. The storage control system according to claim 1, wherein the control unit of said first storage controller stores said restored data in the storage area of said cache memory subject to said purge processing.

2. A storage control system configured by a first storage controller and a second storage controller being connected in a mutually communicable manner, and which performs data processing according to a request from a host system,

said first and second storage controllers respectively comprising:

a storage device;

a logical volume having a logical storage configuration of said storage device and which is accessible from said host system;

a cache memory for storing the data of said logical volume; and

a control unit for controlling the data processing among said storage device, said cache memory and said logical volume;

said first storage controller further comprising a virtual volume associated to the logical volume of said second storage controller without being associated to the storage device of said first storage controller, and which is accessible from said host system;

wherein the control unit of said first storage controller purges the storage area of said cache memory corresponding to a management area of said virtual volume accessed by said host system upon storing restored data of the logical volume of said second storage controller in the cache memory of said first storage controller.

3. The storage control system according to claim 2, wherein the logical volume of said second storage controller comprises a first logical volume and a second logical volume capable of forming a copy-pair relationship, and said first logical volume is associated with said virtual volume.

4. The storage control system according to claim 3, wherein the control unit of said second storage controller copies the stored data of said second logical volume to said first logical volume upon receiving an order for said restoration, and further forwards to said virtual volume the date copied to said first logical volume.

5. The storage control system according to claim 2, wherein the logical volume of said first storage controller is in a copy-pair relationship with said virtual volume.

6. The storage control system according to claim 4, wherein the control unit of said first storage controller issues said restoration order to the control unit of said second storage controller.

7. The storage control system according to claim 4, wherein said host system issues said restoration order to the control unit of said second storage controller.

15. The storage control system according to claim 2, wherein another host system is connected to the logical volume of said second storage controller, and the restored data of said host system is stored in said logical volume.

16. The storage control system according to claim 3, wherein another logical volume having a copy-pair relationship with said volume is provided to said first storage controller.

18. The storage control system according to claim 2, wherein said purge processing is for the control unit of said first storage controller to set a control code indicating to said management area that the stored data in said cache memory storage area is invalid.

20. A storage control method to be applied in a storage control system in which a first storage controller and a second storage controller are connected in a mutually communicable manner, and which is for performing data processing according to a request from a host system,

said first storage controller comprising:

a virtual volume associated with a logical volume of said second storage controller;

a cache memory associated with said virtual volume; and

a control unit for controlling the data processing between said cache memory and said virtual volume;

wherein said control unit executes the step of purging the storage area of said cache memory corresponding to said virtual logical volume accessed by said host system upon storing restored data of said logical volume in said cache memory.