Storage system, method of controlling storage system, and storage device

• US 7,185,152 B2
• Filed: 08/04/2005
• Issued: 02/27/2007
• Est. Priority Date: 09/01/2003
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Satoh, Takao, Ozawa, Koji, Takahashi, Masamitsu
• Primary Examiner(s): Portka; Gary
• Assistant Examiner(s): Doan; Duc T
• Application Number:
  US11/196,418
• Publication Number:
  US 20060004894A1
• Time in Patent Office: 572 Days
• Field of Search: None
• US Class Current: 711/154
• CPC Class Codes: G06F 11/2038 with a single idle spare processing component
• CPC Class Codes: G06F 11/2058 using more than 2 mirrored copies
• CPC Class Codes: G06F 11/2064 while ensuring consistency
• CPC Class Codes: G06F 11/2066 Optimisation of the communication load
• CPC Class Codes: G06F 11/2069 Management of state, configuration or failover
• CPC Class Codes: G06F 11/2071 using a plurality of controllers
• CPC Class Codes: G06F 11/2074 Asynchronous techniques
• CPC Class Codes: G06F 11/2082 Data synchronisation
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

The present invention provides a storage system and a method of controlling the storage system, in which a second site rapidly resumes system process when a first site is damaged. The storage system comprises a first site including a first storage device, a second site including a second storage device, and a third site including a third storage device, and the method of controlling the storage system comprises a step of making a logical volume of the second storage device consistent with a logical volume of the first storage device by remotely copying only the differential data between the logical volume of the first storage device and the logical volume of the second storage device from a logical volume of the third storage device to the logical volume of the second storage device when the first site is damaged.

Claims

1. A remote copy system comprising;

a first storage apparatus, including a first controller and a first logical volume, to be coupled to an information processing apparatus;

a second storage apparatus including a second controller and a second logical volume; and

a third storage apparatus including a third controller and a third logical volume,

wherein when data from the information processing apparatus to the first logical volume are received by the first storage apparatus, the first storage apparatus transmits the data to the third storage apparatus to store the data in the third logical volume, transmits a completion report of writing to the information processing apparatus after transmitting the data to the third storage apparatus, and stores the data in the first logical volume,

wherein the first storage apparatus transmits portions of data of the first logical volume to the second storage apparatus, based on predetermined events, to store the portions of data in the second logical volume,

wherein the third storage apparatus has location information, recorded in a plurality of memory areas in the third storage apparatus, and indicating storing locations, in the third logical volume, of data received from the first storage apparatus, and

wherein the third storage apparatus deletes a part of the location information recorded in one of the plurality of memory areas in the third storage apparatus at a timing related to at least one of the predetermined events.

2. A remote copy system according to claim 1,

wherein the part of the location information deleted by the third storage apparatus indicates storing locations of data corresponds to data received by the second storage apparatus.

3. A remote copy system according to claim 1,

wherein after each of the predetermined events, the first storage apparatus transmits one of the portions of data of the first logical volume to the second storage apparatus.

4. A remote copy system according to claim 3,

wherein after completion of transmission of one of the portions of data of the first logical volume to the second storage apparatus, the first storage apparatus starts transmission of a subsequent one of the portions of data of the first logical volume to the second storage apparatus under the control of the predetermined events.

5. A remote copy system according to claim 1,

wherein the third storage apparatus is configured to transmit a part of data of the third logical volume to the second storage apparatus to store in the second logical volume by using the location information, in case of a failure related to the first storage apparatus.

6. A remote copy system according to claim 5,

wherein the third storage apparatus is configured to select the part of data of the third logical volume by using the location information, and transmit the selected part of data to the second storage apparatus to store in the second logical volume, in case of the failure related to the first storage apparatus.

7. A remote copy system according to claim 1,

wherein the location information is recorded in a form of a plurality of tables in the plurality of memory areas.

8. A remote copy system according to claim 1,

wherein the location information is recorded in a form of a plurality of bitmaps in the plurality of memory areas.

9. A remote copy system comprising:

a first storage apparatus including a first controller and a first logical volume configured by at least one first disk;

a second storage apparatus including a second controller and a second logical volume configured by at least one second disk, wherein data of the first logical volume are transmitted to the second storage apparatus, by an asynchronous remote copy procedure, to be stored in the second logical volume; and

a third storage apparatus including a third controller and a third logical volume configured by at least one third disk, wherein data of the first logical volume are transmitted to the third storage apparatus, by a synchronous remote copy procedure, to be stored in the third logical volume,

wherein the third storage apparatus records location information corresponding to storing locations, in the third logical volume, of data received from the first storage apparatus by using two bitmaps,

wherein for the asynchronous remote copy procedure, the first storage apparatus manages transmission of data of the first logical volume by changing a status of data between two statuses,

wherein in a first status, data are held in the first storage apparatus, and in a second status, data are transmitted to the second storage apparatus,

wherein while a first set of data in the second status is transmitted to the second storage apparatus, a second set of data is kept in the first status, and after completion of transmission of the first set of data, the status of the second set of data is changed from the first status to the second status and the second set of data is transmitted to the second storage apparatus, and

wherein at a timing related to at least one change of a status of data between the two statuses, the third storage apparatus clears one of the two bitmaps.

10. A remote copy system according to claim 9,

wherein at the timing related to at least one change of a status of data between the two statuses, the third storage apparatus clears one of the two bitmaps, on which location information corresponding to data already received by the second storage apparatus is recorded.

11. A remote copy system according to claim 9,

wherein at the timing related to at least one change of a status of data between the two statuses, the one of the two bitmaps, on which location information corresponding to data already received by the second storage apparatus is recorded, is selected to be cleared by the third storage apparatus.

12. A remote copy system according to claim 9,

wherein the third storage apparatus is configured to transmit a part of data stored in the third local volume to the second storage apparatus to store the part of data in the second logical volume by using the location information, in case of a failure related to the first storage apparatus.

13. A remote copy system according to claim 9,

wherein the third storage apparatus is configured to transmit a part of data stored in locations in the third logical volume, which locations are indicated by the location information, to the second storage apparatus to store the part of data in the second logical volume, in case of a failure related to the first storage apparatus.

14. A remote copy system comprising:

a first storage apparatus including a first logical volume;

a second storage apparatus, including a second logical volume, to which data of the first logical volume are transmitted, asynchronously with receiving the data at the first storage apparatus, to be stored in the second logical volume; and

a third storage apparatus, including a third logical volume, to which data of the first logical volume are transmitted, asynchronously with receiving the data at the first storage apparatus, to be stored in the third logical volume,

wherein the third storage apparatus manages location information, recorded in a plurality of memory areas, corresponding to storing locations, in the third logical volume, of data received from the first storage apparatus,

wherein the first storage apparatus manages transmission of data of the first logical volume to the second storage apparatus, by status changes of data between two statuses,

wherein first data, in a first status, are held in the first storage apparatus, while second data, in a second status, are transmitted to the second storage apparatus, and after completion of transmission of the second data, the first data is changed from being in the first status to being in the second status and the first data are transmitted to the second storage apparatus, and

wherein at a timing related to at least one status change of data, the third storage apparatus deletes a part of the location information recorded in one of the plurality of memory areas.

15. A remote copy system according to claim 14,

wherein the part of the location information deleted by the third storage apparatus corresponds to data already received by the second storage apparatus.

16. A remote copy system according to claim 14,

wherein the third storage apparatus is configured to transmit a part of data of the third logical volume to the second storage apparatus to store the part of data in the second logical volume by using the location information, when a site, in which the first storage apparatus is located, is damaged.

17. A remote copy system according to claim 16,

wherein the third storage apparatus is configured to select the part of data of the third logical volume according to the location information, and transmit the selected data to the second storage apparatus to store the selected data in the second logical volume, when a site, in which the first storage apparatus is located, is damaged.

18. A remote copy system according to claim 14,

wherein, in the plurality of memory areas, a plurality of bitmaps recording the location information are configured, and

wherein, at the timing related to at least one status change of data, the third storage apparatus deletes the part of the location information recorded on one of the plurality of bitmaps.

19. A remote copy system according to claim 14,

wherein, in the plurality of memory areas, a plurality of tables for recording the location information are configured, and

wherein, at the timing related to at least one status change of data, the third storage apparatus deletes the part of the location information recorded on one of the plurality of tables.