Storage system

• US 20050073887A1
• Filed: 11/17/2004
• Published: 04/07/2005
• Est. Priority Date: 06/27/2003
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Sato, Takao, Arakawa, Hiroshi, Hirakawa, Yusuke, Takeda, Takahiko
• Granted Patent: US 7,725,445 B2
• Time in Patent Office: Days
• US Class Current: 365/189.50
• CPC Class Codes: G06F 11/2064 while ensuring consistency
• CPC Class Codes: G06F 11/2071 using a plurality of controllers
• CPC Class Codes: G06F 11/2082 Data synchronisation
• CPC Class Codes: G06F 16/22 Indexing; Data structures therefor; Storage structures
• CPC Class Codes: G06F 2201/855 Details of asynchronous mirroring using a journal to transfer not-yet-mirrored changes
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

A first storage system stores information relating to the updating of data stored in that system as a journal. More specifically, the journal is composed of a copy of data that was used for updating and update information such as a write command used during updating. Furthermore, the second storage system acquires the journal via a communication line between the first storage system and the second storage system. The second storage system holds a duplicate of the data held by the first storage system and updates the data corresponding to the data of the first storage system in the data update order of the first storage system by using the journal.

Claims

1. A storage system group comprising:

a first storage system connected to a host device for sending data to and receiving data from said host device; and

a second storage system connected to said first storage system for receiving data from said first storage system,

wherein said first storage system comprises;

a first storage area for writing data sent from said host device; and

a second storage area for writing the data written in said first storage area and update information relating to said data;

said second storage system comprises a third storage area for storing the data read from said second storage area and update information relating to said data; and

the data and update information stored in said third storage area are read from said first storage system at prescribed time intervals.

2. The storage system group according to claim 1, wherein said second storage system conducts the control so as to determine said prescribed time intervals according to a number of data read from said second storage area.

3. The storage system group according to claim 1, wherein said second storage system conducts the control so as to determine said prescribed time intervals according to a traffic of data sent and received between said first storage system and said second storage system.

4. The storage system group according to claim 1, wherein said second storage system conducts the control so as to determine said prescribed time intervals according to a storage capacity held by said third storage area.

5. The storage system group according to claim 1, wherein said second storage system conducts the control so as to determine said prescribed time intervals according to a processing load of said second storage system itself.

6. The storage system group according to claim 1, wherein said second storage system reads from said first storage system the information relating to the storage capacity held by said second storage area in said first storage system and conducts the control so as to determine said prescribed time intervals according to said information thus read.

7. The storage system group according to claim 1, wherein the update information to be written into said second storage area relates to the update sequence of the data that is to be written into said first storage area.

8. The storage system group according to claim 7,

wherein said first storage system possesses management information relating to said second storage area;

and

said second storage system reads from said first storage system the management information relating to said second storage area which is possessed by said first storage system and conducts the control so as to determine said prescribed time intervals according to said management information thus read.

9. The storage system group according to claim 1,

wherein a plurality of said first storage areas are present;

and

the information that will be written in said second storage area is created by taking as the object the data that will be written in said plurality of first storage areas.

10. The storage system group according to claim 9, wherein the update information to be written in said second storage area relates to the update sequence of the data that is to be written in said plurality of first storage areas.

11. The storage system group according to claim 9,

wherein said first storage system allocates said second storage area as a store area for the update information of the data that is to be written in said plurality of first storage areas and possesses the management information relating to said second storage area;

and

said second storage system reads from said first storage system the management information relating to said second storage area possessed by said first storage system and

conducts the control so as to determine said prescribed time intervals according to said management information thus read.

12. The storage system group according to claim 1,

wherein said second storage system transmits a command requiring the forwarding of the data stored in said second storage area and the update information relating to said data to said first storage system at said prescribed time intervals;

and

said first storage system transmits the data stored in said second storage area and the update information relating to said data to said second storage system in response to said command.

13. The storage system group according to claim 1, wherein said second storage system has a fourth storage area corresponding to said first storage area in said first storage system and stores data in said fourth storage area based on the update information and data stored in said third storage area.

14. The storage system group according to claim 13, wherein said second storage system controls the timing of the process for storing data in said fourth storage area according to a processing load of said second storage system itself.

15. The storage system group according to claim 1,

wherein said first storage system comprises a host adapter for sending data to and receiving data from the host device, a cache for retaining the data received by said host adapter, a disk adapter for transferring the data stored in said cache, and a plurality of disk drives for storing the data according to said disk adapter control;

and

said first storage area and said second storage area are allocated from a storage area in said plurality of disk drives.

16. The storage system group according to claim 1,

wherein said second storage system comprises a host adapter for sending data to and receiving data from the host device, a cache for retaining the data received by said host adapter, a disk adapter for transferring the data stored in said cache, and a plurality of disk drives for storing the data according to said disk adapter control;

and

said third storage area is allocated from a storage area in said plurality of disk drives.

17. A storage system group comprising:

a first storage system connected to a host device for sending data to and receiving data from said host device;

a second storage system connected to said first storage system for receiving data from said first storage system; and

a third storage system connected to said second storage system for receiving data from said second storage system;

wherein said first storage system comprises a first storage area for writing data sent from said host device;

said second storage system comprises a second storage area for writing the data written in said first storage area in said first storage system and update information relating to said data;

said third storage system comprises a third storage area for storing the data read from said second storage area in said second storage system and update information relating to said data; and

the data and update information to be stored in said third storage area are read from said second storage system at a prescribed time intervals.

18. The storage system group according to claim 17,

wherein said third storage system conducts the control so as to determine said prescribed time intervals according to a number of data read from said second storage area.

19. The storage system group according to claim 17, wherein said third storage system conducts the control so as to determine said prescribed time intervals according to a traffic of data exchanged between said second storage system and said third storage system.

20. The storage system group according to claim 17, wherein said third storage system conducts the control so as to determine said prescribed time intervals according to a storage capacity held by said third storage area.

21. The storage system group according to claim 17, wherein said third storage system conducts the control so as to determine said prescribed time intervals according to a processing load of said third storage system itself.

22. The storage system group according to claim 17, wherein said third storage system reads from said second storage system the information relating to the storage capacity held by said second storage area in said second storage system and conducts the control so as to determine said prescribed time intervals according to said information thus read.

23. The storage system group according to claim 17, wherein the update information to be written into said second storage area relates to the update sequence of the data that is to be written into said second storage area.

24. The storage system group according to claim 23,

wherein said second storage system possesses management information relating to said second storage area;

and

said third storage system reads from said second storage system management information relating to said second storage area which is possessed by said second storage system and conducts the control so as to determine said prescribed time intervals according to said management information thus read.

25. The storage system group according to claim 17,

wherein said third storage system transmits a command requiring the forwarding of the data stored in said second storage area and update information relating to said data to said second storage system at said prescribed time intervals;

and

said second storage system transmits the data stored in said second storage area and the update information relating to said data to said third storage system in response to said command.

26. The storage system group according to claim 17, wherein said third storage system has a fourth storage area corresponding to said first storage area in said first storage system and stores data in said fourth storage area based on the data and update information stored in said third storage area.

27. The storage system group according to claim 26, wherein said third storage system controls the timing of the process for storing data in said fourth storage area according to a processing load of said third storage system itself.

28. The storage system group according to claim 17, wherein when said first storage system has written data sent from said host device to said first storage area, the first storage system transmits the data written in said first storage area to said second storage system;

and

said second storage system writes the data written in said first storage area of said first storage system and update information relating to said data into said second storage area.

29. A storage system group comprising:

a first storage system connected to a host device for sending data to and receiving data from said host device;

a second storage system connected to said first storage system for receiving data from said first storage system; and

a third storage system connected to said second storage system for receiving data from said second storage system;

wherein said first storage system comprises a first storage area for writing data sent from said host device;

said second storage system comprises a second storage area for writing data sent from said first storage system and a third storage area for writing the data written into said second storage area and update information relating to said data;

said third storage system comprises a fourth storage area for storing data read from said third storage area in said second storage system and update information relating to said data; and

the data and update information to be stored in said fourth storage area are read from said third storage system at the prescribed time intervals.

30. The storage system group according to claim 29, wherein said third storage system conducts the control so as to determine said prescribed time intervals according to a number of data read from said third storage area.

31. The storage system group according to claim 29, wherein said third storage system conducts the control so as to determine said prescribed time intervals according to a traffic of data exchanged between said second storage system and said third storage system.

32. The storage system group according to claim 29, wherein said third storage system conducts the control so as to determine said prescribed time intervals according to a storage capacity held by said fourth storage area.

33. The storage system group according to claim 29, wherein said third storage system conducts the control so as to determine said prescribed time intervals according to a processing load of said third storage system itself.

34. The storage system group according to claim 29, wherein said third storage system reads from said second storage system information relating to the storage capacity held by said third storage area in said second storage system and conducts the control so as to determine said prescribed time intervals according to said information thus read.

35. The storage system group according to claim 29, wherein the update information to be written into said third storage area relates to the update sequence of the data to be written into said second storage area.

36. The storage system group according to claim 35,

wherein said second storage system possesses management information relating to said third storage area;

and

said third storage system reads from said second storage system the management information relating to said third storage area which is possessed by said second storage system and conducts the control so as to determine said prescribed time intervals according to said management information thus read.

37. The storage system group according to claim 29,

wherein said third storage system transmits a command requiring the forwarding of data stored in said second storage area and the update information relating to said data to said second storage system at said prescribed time intervals;

and

said second storage system transmits the data stored in said third storage area and update information relating to said data to said third storage system in response to said command.

38. The storage system group according to claim 29, wherein said third storage system has a fifth storage area corresponding to said second storage area in said second storage system and stores data in said fifth storage area based on the data and update information stored in said fourth storage area.

39. The storage system group according to claim 38, wherein said third storage system controls the timing of the process for storing data in said fifth storage area according to a processing load of said third storage system itself.