Storage system for multi-site remote copy

• US 7,343,461 B2
• Filed: 09/08/2006
• Issued: 03/11/2008
• Est. Priority Date: 07/30/2002
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nakano, Toshio, Morishita, Noboru, Higaki, Seiichi
• Primary Examiner(s): Thai; Tuan V.
• Application Number:
  US11/517,380
• Publication Number:
  US 20070005917A1
• Time in Patent Office: 550 Days
• Field of Search: 711/100, 711/147, 711/151, 711/154, 711/161, 711/162, 714/1, 714/13, 714/15
• US Class Current: 711/162
• CPC Class Codes: G06F 11/2058 using more than 2 mirrored copies
• CPC Class Codes: G06F 11/2069 Management of state, configuration or failover
• CPC Class Codes: G06F 11/2074 Asynchronous techniques
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• 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]

Abstract

Information about remote copy target volumes of other storage systems 2 each having one and the same original volume V1 is registered for each remote copy target volume in advance. When there occurs a failure in a copy source storage system 2, a copy source volume for remote copy target volumes using the storage system 2 having a failure as their copy source is selected newly from the registered copy source volumes, and remote copy is resumed.

Claims

1. A storage system comprising:

a first disk array system, adapted to be coupled to a host computer, and comprising a plurality of first disk drive units in which data are stored and a first controller which controls storing of data sent from said host computer to a primary volume related to at least a portion of said first disk drive units;

a second disk array system, adapted to be coupled to said first disk array system, and comprising a plurality of second disk drive units in which data are stored and a second controller which receives data of said primary volume from said first disk array system by an asynchronous remote copy procedure and controls storing of data received from said first disk array system to a secondary volume related to at least a portion of said second disk drive units; and

a third disk array system, adapted to be coupled to said first disk array system, and comprising a plurality of third disk drive units in which data are stored and a third controller which receives data of said primary volume from said first disk array system by a synchronous remote copy procedure and controls storing of data received from said first disk array system to a third volume related to at least a portion of said third disk drive units,

wherein said third disk array system is adapted to comprise a first bitmap and a second bitmap, said first bitmap storing information related to data of a plurality of write requests received from said first disk array system during a first time period, said second bitmap storing information related to data of a plurality of write requests received from said first disk array system during a second time period which is different from said first time period.

2. A storage system according to claim 1, wherein said synchronous remote copy procedure is a copy procedure in which said first disk array system sends an acknowledgment to said host computer after said third disk array system receives first data sent from said first disk array system, if said first disk array system receives said first data sent from said host computer.

3. A storage system according to claim 1, wherein said asynchronous remote copy procedure is a copy procedure in which said first disk array system sends an acknowledgment to said host computer without regard to whether said third disk array system receives second data sent from said first disk array system, if said first disk array system receives said second data sent from said host computer.

4. A storage system according to claim 1, wherein said third disk array system is adapted to change a bitmap, which stores information related to data of a plurality of write requests received from said first disk array system, from said first bitmap to said second bitmap based on communication from said first disk array system to said third disk array system.

5. A storage system according to claim 1, wherein, in the event of a disaster that affects said first disk array system, said second disk array system or said third disk array system is adapted to function as a source disk array system, which transfers data to be copied to a target disk array system.

6. A storage system according to claim 1, wherein, in the event of a disaster that affects said first disk array system, said second disk array system or said third disk array system is adapted to function as a target disk array system, which receives data to be copied from a source disk array system.

7. A storage system according to claim 1, wherein said third disk array system is adapted to stop to store information, related to data of a plurality of write requests received from said first disk array system by said synchronous remote copy procedure, in said first area after said first time period.

8. A storage system according to claim 1, wherein said second disk array system is adapted to comprise a third bitmap, said third bitmap storing information related to data of a plurality of write requests received from said first disk array system by said asynchronous remote copy procedure during said second time period.

9. A storage system according to claim 1, wherein said second disk array system is adapted to comprise a third bitmap, said third bitmap storing information related to data of a plurality of write requests received from said first disk array system during said second time period, and

wherein, in the event of a disaster that affects said first disk array system, information regarding most current data are stored in said second bitmap or said third bitmap.

10. A storage system according to claim 1, wherein said information stored in said second bitmap is used to decide data to be transferred from said third disk array system to said second disk array system in the event of a disaster that affects said first disk array system.

11. A storage system according to claim 1, wherein said first bitmap indicates a storing location in which data received from said first disk array system are stored.

12. A storage system according to claim 1, wherein one of said secondary volume and said third volume, which stores more current data, is selected as a copy source in the event of a disaster that affects said first disk array system.

13. A storage system according to claim 1, wherein one of the second disk array system and said third disk array system, which stores more current data, is adapted to be selected as a copy source in the event of a disaster that affects said first disk array system.

14. A storage system according to claim 1, wherein one of the second disk array system and said third disk array system, which stores more current data, is adapted to be selected after a disaster that affects said first disk array system, and

wherein said selected disk array system transfers the most current data after said disaster.

15. A storage system comprising:

a first disk array system, adapted to be coupled to a host computer, and comprising a plurality of first disk drive units in which data are stored and a first controller which controls storing of data sent from said host computer to a primary volume related to at least a portion of said first disk drive units;

a second disk array system adapted to be coupled to said first disk array system, and comprising a plurality of second disk drive units in which data are stored and a second controller which receives data of said primary volume from said first disk array system by an asynchronous remote copy procedure and controls storing of data received from said first disk array system to a secondary volume related to at least a portion of said second disk drive units; and

a third disk array system, adapted to be coupled to said first disk array system, and comprising a plurality of third disk drive units in which data are stored and a third controller which receives data of said primary volume from said first disk array system by a synchronous remote copy procedure and controls storing of data received from said first disk array system to a third volume related to at least a portion of said third disk drive units,

wherein said third disk array system is adapted to include a first bitmap and a second bitmap, said first bitmap storing information related to data of a plurality of write requests received from said first disk array system by said synchronous remote copy procedure during a first time period, said second bitmap storing information related to data of a plurality of write requests received from said first disk array system by said synchronous remote copy procedure during a second time period which is different from said first time period.

16. A storage system comprising:

a first disk array system, adapted to be coupled to a host computer, and comprising a plurality of first disk drive units in which data are stored and a first controller which controls storing of data sent from said host computer to a primary volume related to at least a portion of said first disk drive units;

a second disk array system, adapted to be coupled to said first disk array system, and comprising a plurality of second disk drive units in which data are stored and a second controller which receives data of said primary volume from said first disk array system by an asynchronous remote copy procedure and controls storing of data received from said first disk array system to a secondary volume related to at least a portion of said second disk drive units; and

a third disk array system, adapted to be coupled to said first disk array system, and comprising a plurality of third disk drive units in which data are stored and a third controller which receives data of said primary volume from said first disk array system by a synchronous remote copy procedure and controls storing of data received from said first disk array system to a third volume related to at least a portion of said third disk drive units,

wherein said third disk array system is adapted to relate to a first bitmap and a second bitmap, said first bitmap indicating information related to data received from said first disk array system based on said synchronous remote copy procedure during a first time period, said second bitmap indicating information related to data received from said first disk array system based on said synchronous remote copy procedure during a second time period which is different from said first time period, and

wherein, in the event of a disaster that affects said first disk array system, one of said second disk array system and said third disk array system is adapted to function as a source disk array system, which transfers data to be copied to another of said second disk array system and said third disk array system as a target disk array system.

17. A storage system comprising:

a first disk array system, adapted to be coupled to a host computer, and comprising a plurality of first disk drive units in which data are stored and a first controller which controls storing of data sent from said host computer to a primary volume related to at least a portion of said first disk drive units;

a second disk array system, adapted to be coupled to said first disk array system, and comprising a plurality of second disk drive units in which data are stored and a second controller which receives data of said primary volume from said first disk array system by an asynchronous remote copy procedure and controls storing of data received from said first disk array system to a secondary volume related to at least a portion of said second disk drive units;

a third disk array system, adapted to be coupled to said first disk array system, and comprising a plurality of third disk drive units in which data are stored and a third controller which receives data of said primary volume from said first disk array system by a synchronous remote copy procedure and controls storing of data received from said first disk array system to a third volume related to at least a portion of said third disk drive units;

a first bitmap, in said third disk array system, adapted to indicate information related to data received from said first disk array system during a first time period; and

a second bitmap, in said third disk array system, adapted to indicate information related to data received from said first disk array system during a second time period which is different from said first time period,

wherein said second disk array system or said third disk array system is adapted to be decided as a source disk array system, which transfers data to be copied to a target disk array system, in the event of a disaster that affects said first disk array system.

18. A storage system according to claim 17, wherein said third disk array system is adapted to stop to store information related to data received from said first disk array system in said first bitmap after said first time period.

19. A storage system according to claim 17, wherein when said disaster occurs, it becomes impossible to communicate between said first disk array system and said third disk array system.

20. A storage system comprising:

a first disk array system, configured to be coupled to a host computer, and comprising a plurality of first disk drive units in which data are stored and a first controller which controls storing of data sent from said host computer to a primary volume related to at least a portion some of said first disk drive units;

a second disk array system, configured to be coupled to said first disk array system, and comprising a plurality of second disk drive units in which data are stored and a second controller which receives data of said primary volume from said first disk array system by an asynchronous remote copy procedure and controls storing of data received from said first disk array system to a secondary volume related to at least a portion of said second disk drive units;

a third disk array system, configured to be coupled to said first disk array system, and comprising a plurality of third disk drive units in which data are stored and a third controller which receives data of said primary volume from said first disk array system by a synchronous remote copy procedure and controls storing of data received from said first disk array system to a third volume related to at least a portion of said third disk drive units,

wherein said third disk array system is configured to store information related to data of a plurality of write requests received from said first disk array system by said synchronous remote copy procedure in said first area during a first time period and to store information related to data of a plurality of write requests received from said first disk array system by said synchronous remote copy procedure in said second area during a second time period which is different from said first time period.

21. A storage system comprising:

a first disk array system, configured to be coupled to a host computer, and comprising a plurality of first disk drive units in which data are stored and a first controller which controls storing of data sent from said host computer to a primary volume related to at least a portion of said first disk drive units;

a second disk array system, configured to be coupled to said first disk array system, and comprising a plurality of second disk drive units in which data are stored and a second controller which receives data of said primary volume from said first disk array system by an asynchronous remote copy procedure and controls storing of data received from said first disk array system to a secondary volume related to at least a portion said second disk drive units; and

a third disk array system, configured to be coupled to said first disk array system, and comprising a plurality of third disk drive units in which data are stored and a third controller which receives data of said primary volume from said first disk array system by a synchronous remote copy procedure and controls storing of data received from said first disk array system to a third volume related to at least a portion of said third disk drive units,

wherein said third disk array system is configured to relate to a first bitmap and a second bitmap, said first bitmap related to information of data of a plurality of write requests received from said first disk array system during a first time period, said second bitmap related to information of data of a plurality of write requests received from said first disk array system during a second time period which is different from said first time period, and

wherein, after said first disk array system has a failure, said third disk array system is configured to transfer data, which are not stored in said second disk array system, to said second disk array system by using said second bitmap.