Data processing system

• US 20070038824A1
• Filed: 10/17/2006
• Published: 02/15/2007
• Est. Priority Date: 09/09/2003
• Status: Active Grant

• Current Assignee: Kazuhito Suishu, Yoshihiro Asaka, Yusuke Hirakawa
• Original Assignee: Kazuhito Suishu, Yoshihiro Asaka, Yusuke Hirakawa
• Inventors: Hirakawa, Yusuke, Asaka, Yoshihiro, Suishu, Kazuhito
• Granted Patent: US 7,447,855 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/201 between storage system components
• 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 11/2082 Data synchronisation
• CPC Class Codes: G06F 2201/855 Details of asynchronous mirroring using a journal to transfer not-yet-mirrored changes
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A data processing system includes at least a first storage system, a second storage system and a third storage system. The third storage system maintains a replication of data stored in the first storage system. When updating data in the first storage system, the first storage system updates the replication of data stored in the third storage system and creates a journal. The journal is formed from a copy of data used for update and update information such as a write command for update, etc. The second storage system also maintains a replication of data stored in the first storage system. The second storage system obtains the journal, and updates data stored therein corresponding to data stored in the first storage system in the order of data update performed in the first storage system. When updating data stored in the third storage system corresponding to data stored in the first storage system, the third storage system creates a journal using data update numbers created in the first storage system. When the first storage system fails, the second storage system obtains the journal from the third storage system, and updates data stored therein corresponding to data stored in the first storage system in the order of data update performed in the first storage system.

Claims

1. A remote copy system comprising:

a first storage system having a first logical volume and a first controller;

a second storage system, having a second logical volume and a second controller, to which data of the first logical volume are transmitted to be stored in the second logical volume by a synchronous remote copy procedure; and

a third storage system, having a third logical volume and a third controller, to which data of the first logical volume and information used for maintaining consistency of data in the third logical volume are transmitted by an asynchronous remote copy procedure;

wherein the third storage system stores the data of the first logical volume received from the first storage system in the third logical volume while maintaining consistency of data in the third logical volume, by using the information received from the first storage system,

wherein the second storage system receives the information used for maintaining consistency of data in the third logical volume from the first storage system and keeps the information, and

wherein when a failure related to the first storage system occurs, the second storage system transmits the information and the data of the second logical volume by the asynchronous remote procedure, and the third storage system stores the data of the second logical volume received from the second storage system in the third logical volume while maintaining consistency of data in the third logical volume, by using the information received from the second storage system.

2. A remote copy system according to claim 1,

wherein when the failure related to the first storage system occurs, the third storage system changes a source storage system, from which data and the information used for maintaining consistency of data in the third logical volume are received, from the first storage system to the second storage system.

3. A remote copy system according to claim 2,

wherein in the asynchronous remote copy procedure, the third storage system transmits a data transfer request to the source storage system and receives data and the information used for maintaining consistency of data in the third logical volume in response to the data transfer request, and

wherein when the failure related to the first storage system occurs, the third storage system changes a destination of the data transfer request from the first storage system to the second storage system.

4. A remote copy system according to claim 1, wherein the information used for maintaining consistency of data in the third logical volume relates to an order of data writing to the first logical volume.

5. A remote copy system comprising:

a first storage having a first logical volume for storing data received from a computer and a first controller;

a second storage system, having a second logical volume and a second controller, wherein a synchronous remote copy pair is configured between the first logical volume and the second logical volume and data received to be stored in the first logical volume are transmitted to be stored in the second logical volume;

a third storage system, having a third logical volume and a third controller, wherein an asynchronous remote copy pair is configured between the first logical volume and the third logical volume, data received to be stored in the first logical volume and information used for maintaining consistency of data in the third logical volume are transmitted to the third storage system, and the data are stored in the third logical volume with data consistency according to the information,

wherein the second storage system receives the information used for maintaining consistency of data in the third logical volume from the first storage system, and when an asynchronous remote copy pair between the second logical volume and the third logical volume is configured, the second storage system transmits the information and data for storing in the second logical volume to the third storage system, and the data are stored in the third logical volume with data consistency according to the information received from the second storage system.

6. A remote copy system according to claim 5,

wherein when the asynchronous remote copy pair between the second logical volume and the third logical volume is configured, the third storage system changes a source storage system, from which data and the information used for maintaining consistency of data in the third logical volume are received, from the first storage system to the second storage system.

7. A remote copy system according to claim 6,

wherein in the asynchronous remote copy procedure, the third storage system transmits a data transfer request to the source storage system and receives data and the information used for maintaining consistency of data in the third logical volume in response to the data transfer request, and

wherein when the asynchronous remote copy pair between the second logical volume and the third logical volume is configured, the third storage system changes a destination of the data transfer request from the first storage system to the second storage system.

8. A remote copy system according to claim 5,

wherein the information used for maintaining consistency of data in the third logical volume relates to an order of data writing to the first logical volume.

9. A remote copy system according to claim 8,

wherein the third storage system stores the data in the third logical volume according to the order of data writing indicated by the information.

10. A method for copying data among a first storage system, a second storage system, and a third storage system, wherein the first storage system has a first logical volume for storing data received from a computer, the second storage system has a second logical volume, to which data received from the first storage system are stored, and the third storage system has a third logical volume, to which data received from the first storage system are stored, the method comprising the steps of:

receiving data to be stored in the first logical volume from the computer by the first storage system;

transmitting the data from the first storage system to the second storage system to store the data in the second logical volume by a synchronous remote copy procedure;

storing the data in the first logical volume of the first storage system;

transmitting the data and information used for maintaining consistency of data in the third logical volume, from the first storage system to the third storage system, to store the data in the third logical volume by an asynchronous remote copy procedure;

transmitting the information used for maintaining consistency of data in the third logical volume;

from the first storage system to the second storage system;

storing the data received from the first storage system in the second logical volume of the second storage system;

keeping the information used for maintaining consistency of data in the third logical volume at the second storage system;

storing the data received from the first storage system in the third logical volume of the third storage system while maintaining consistency of data in the third logical volume according to the information received from the first storage system;

upon a failure related to the first storage system, transmitting the data of the second logical volume and the information maintained at the second storage system from the second storage system to the third storage system; and

storing the data received from the second storage system in the third logical volume while maintaining consistency of data in the third logical volume according to the information received from the second storage system.

11. A method for copying data according to claim 10, further comprising the step of:

when the failure related to the first storage system occurs, changing a source storage system, from which data and the information used for maintaining consistency of data in the third logical volume are received, from the first storage system to the second storage system.

12. A method for copying data according to claim 11, further comprising the steps of:

in the asynchronous remote copy procedure, transmitting a data transfer request to the source storage system and receiving data and the information used for maintaining consistency of data in the third logical volume in response to the data transfer request, and

when the failure related to the first storage system occurs, changing a destination of the data transfer request from the first storage system to the second storage system.

13. A method for copying data according to claim 10, wherein the information used for maintaining consistency of data in the third logical volume relates to an order of data writing to the first logical volume.