System, method and circuit for mirroring data

• US 20060143497A1
• Filed: 12/23/2004
• Published: 06/29/2006
• Est. Priority Date: 12/23/2004
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: XIV Ltd. (International Business Machines Corporation)
• Inventors: Helman, Haim, Zohar, Ofir, Schwartz, Shemer, Revah, Yaron, Cohen, Dror
• Granted Patent: US 7,437,598 B2
• Time in Patent Office: Days
• US Class Current: 714/4
• CPC Class Codes: G06F 11/2058 using more than 2 mirrored copies
• CPC Class Codes: G06F 11/2071 using a plurality of controllers

Abstract

Disclosed is a system, method and circuit for mirroring data on a data server. According to some embodiments of the present invention, a primary mirroring module associated with a primary server may be adapted to establish data mirroring connections between the primary server and both a primary slave mirroring module functionally associated with a primary mirror server and with a secondary slave mirroring module functionally associated with a secondary mirror server. When sensing that a mirroring connection with the primary server has been terminated, the primary slave mirroring module may establish a mirroring connection with the second slave mirroring module and may reconcile data between the primary and secondary mirror servers.

Claims

1. A system for mirroring data on a data server comprising:

a. a primary data server; and

b. a primary mirroring module adapted to be functionally associated with said primary data server and to establish data mirroring connections with a primary slave mirroring module which is functionally associated with a primary mirror server and to establish data mirroring connections with a secondary slave mirroring module which is functionally associated with a secondary mirror server, wherein upon sensing that a mirroring connection with the primary server has been terminated said primary slave mirroring module is adapted to establish a mirroring connection with said second slave mirroring module and to reconcile data between said primary and secondary mirror servers.

2. The system according to claim 1, wherein the primary mirroring module is adapted to establish an asynchronous mirroring connection with one of the mirroring servers.

3. The system according to claim 2, wherein the primary mirroring module is adapted to establish an asynchronous mirroring connection with each of the mirroring servers.

4. The system according to claim 2, wherein the primary mirroring module is adapted to establish a synchronous mirroring connection with the primary mirroring server.

5. The system according to claim 2, wherein reconciling data between the primary and secondary mirroring servers includes checking the integrity of data received from the primary server by each of the mirroring servers.

6. The system according to claim 5, wherein reconciling data between the primary and secondary mirroring servers includes transferring to the primary mirroring server a copy of any complete data which is present on the secondary mirroring server but not on the primary mirroring server.

7. The system according to claim 5, wherein upon reconciling data between themselves, the primary and/or the secondary mirroring servers are adapted to accept data requests.

8. A method of mirroring data on a data server comprising:

establish a data mirroring connections with a primary slave mirroring module which is functionally associated with a primary mirror server and establishing a data mirroring connection with a secondary slave mirroring module which is functionally associated with a secondary mirror server;

upon sensing that a mirroring connection with the primary server has been terminated, establishing a mirroring connection between the primary slave mirroring module and the second slave mirroring module; and

reconciling data between the primary and secondary mirror servers.

9. The method according to claim 8, wherein establish a mirroring connection includes establishing an asynchronous mirroring connection with one of the mirroring servers.

10. The method according to claim 8, wherein establishing a mirroring connection includes establish an asynchronous mirroring connection with each of the two mirroring servers.

11. The method according to claim 8, wherein establishing a mirroring connection includes establish a synchronous mirroring connection with the primary mirroring server.

12. The method according to claim 8, wherein reconciling data between the primary and secondary mirroring servers includes checking the integrity of data received from the primary server by each of the mirroring servers.

13. The method according to claim 12, wherein reconciling data between the primary and secondary mirroring servers includes transferring to the primary mirroring server a copy of any complete data which is present on the secondary mirroring server but not on the primary mirroring server.

14. The method according to claim 13, wherein upon reconciling data between themselves, the primary and/or the secondary mirroring servers accepting data requests.

15. A circuit for mirroring data on a data server comprising:

a logic circuit or processor functionally associated with said server and adapted to execute functional modules, including a primary mirroring module adapted to establish data mirroring connections between said server and both a primary slave mirroring module which is functionally associated with a primary mirror server and with a secondary slave mirroring module which is functionally associated with a secondary mirror server, wherein upon sensing that a mirroring connection with the primary server has been terminated said primary slave mirroring module is adapted to establish a mirroring connection with said second slave mirroring module and to reconcile data between said primary and secondary mirror servers.

16. The circuit according to claim 15, wherein the primary mirroring module is adapted to establish an asynchronous mirroring connection with one of the mirroring servers.

17. The circuit according to claim 15, wherein the primary mirroring module is adapted to establish an asynchronous mirroring connection with each of the mirroring servers.

18. The circuit according to claim 15, wherein the primary mirroring module is adapted to establish a synchronous mirroring connection with the primary mirroring server.

19. The circuit according to claim 15, wherein reconciling data between the primary and secondary mirroring servers includes checking the integrity of data received from the primary server by each of the mirroring servers.

20. The circuit according to claim 19, wherein reconciling data between the primary and secondary mirroring servers includes transferring to the primary mirroring server a copy of any complete data which is present on the secondary mirroring server but not on the primary mirroring server.

21. The circuit according to claim 20, wherein upon reconciling data between themselves, the primary and/or the secondary mirroring servers are adapted to accept data requests.