System and method for verifying the consistency of mirrored data sets

• US 7,702,869 B1
• Filed: 12/08/2008
• Issued: 04/20/2010
• Est. Priority Date: 04/28/2006
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Yadav, Vikas
• Primary Examiner(s): Verbrugge; Kevin
• Application Number:
  US12/330,013
• Time in Patent Office: 498 Days
• Field of Search: None
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/1458 Management of the backup or restore process
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/1612 where the redundant component is persistent storage
• CPC Class Codes: G06F 2201/82 Solving problems relating to consistency ensuring consistency in mirrored systems G06F11/2064
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data

Abstract

A system and method for verifying the consistency of mirrored data sets is provided. A verification module executed on a destination storage system transmits a list of desired persistent consistency point images (PCPIs) to a source destination storage system. The source destination storage system identifies a common subset of PCPIs and returns a list of the common subset to the destination. The destination initiates a separate connection for each PCPI in the common subset. The source then generates a data stream which is transmitted to the destination for use in verifying the PCPIs.

Claims

1. A system, comprising:

a first storage system configured to execute a verification daemon, the verification daemon configured to compare a first list of persistent consistency point images (PCPIs) stored on the first storage system with a second list of PCPIs sent from a verification module configured to execute on a second storage system to determine a common list of PCPIs;

the first storage system further configured to create a stream of verification data for at least one PCPI in the common list of PCPIs and further configured to send the stream of verification data to the second storage system; and

the second storage system configured to compare the stream of verification data with local data of the second storage system.

2. The system of claim 1, wherein the stream of verification data comprises checksum information.

3. The system of claim 1, wherein the stream of verification data comprises metadata information.

4. The system of claim 1, wherein the stream of verification data comprises one or more persistent consistency point images.

5. The system of claim 1, wherein the verification daemon is further configured to lock the at least one PCPI in the common list of PCPIs.

6. The system of claim 1, wherein the second storage system is further configured to display status information about the at least one PCPI in the common list of PCPIs.

7. The system of claim 1, wherein the first storage system is further configured with a processor, a memory, a storage operating system, a network adapter and a storage adapter, wherein the first storage system is connected to a plurality of storage devices.

8. The system of claim 1, wherein the second storage system is further configured with a processor, a memory, a storage operating system, a network adapter and a storage adapter, wherein the second storage system is connected to a plurality of storage devices.

21. The system of claim 1, wherein the stream of verification data is sent via a file system independent protocol format.

22. The system of claim 1, wherein the verification module is further configured to modify the second storage system in response to a mismatch between the stream of verification data and the local data.

23. The system of claim 1, wherein the verification module is automatically invoked.

24. The system of claim 1, wherein the stream of verification data is in a format utilized by a mirroring application.

25. The system of claim 1, wherein the first and the second list each comprise a single PCPI.

9. A method, comprising:

executing a verification daemon on a first storage system;

sending, by a verification module executing on a second storage system, a list of persistent consistency point images (PCPIs) to the first storage system;

comparing, by the verification daemon, a list of PCPIs stored on the first storage system with the list of PCPIs sent from the second storage system;

determining, in response to comparing both lists of PCPIs, a common list of PCPIs;

creating a stream of verification data for at least one PCPI in the common list of PCPIs;

sending the stream of verification data to the second storage system; and

comparing the stream of verification data with local data of the second storage system.

10. The method of claim 9, wherein the stream of verification data comprises checksum information.

11. The method of claim 9, wherein the stream of verification data comprises metadata information.

12. The method of claim 9, wherein the stream of verification data comprises one or more PCPIs.

13. The method of claim 9, further comprising locking, by the verification daemon, the at least one PCPI in the common list of PCPIs.

14. The method of claim 9, further comprising displaying, by the second storage system, status information about the at least one PCPI in the common list of PCPIs.

15. The method of claim 9, wherein the verification daemon is executed in response to receiving a connection request sent from the verification module executed by the second storage system.

16. The method of claim 9, wherein creating the stream of verification data for the at least one PCPI further comprises initiating a new verification thread for the at least one PCPI.

17. The method of claim 16, wherein initiating the new verification thread for each the at least one PCPI further comprises generating a new thread to process operations specific to the at least one PCPI in the common list of PCPIs.

18. The method of claim 16, wherein the step of initiating the new verification thread for the at least one PCPI further comprises generating the stream of verification data for the at least one PCPI in the common list of PCPIs.

19. The method of claim 18, wherein the stream of verification data comprises checksum information of the at least one PCPI.

26. The method of claim 9, wherein the stream of verification data is sent via a file system independent protocol format.

27. The method of claim 9, further comprising modifying, by the verification module, the second storage system in response to a mismatch between the stream of verification data and the local data.

28. The method of claim 9, wherein the verification module is automatically invoked.

29. The method of claim 9, wherein the stream of verification data is in a format utilized by a mirroring application.

30. The method of claim 9, wherein the list stored on the first storage system and the list sent from the second storage system each comprise a single PCPI.

20. A computer readable medium containing executable program instructions executed by a processor, comprising:

program instructions that execute a verification daemon on a first storage system;

program instructions that send, by a verification module configured to execute on a second storage system, a list of persistent consistency point images (PCPIs) to the first storage system;

program instructions that compare, by the verification daemon, a list of PCPIs stored on the first storage system with the list of PCPIs sent from the second storage system;

program instructions that determine, in response to comparing both lists of PCPIs, a common list of PCPIs;

program instructions that create a stream of verification data for at least one PCPI in the common list of PCPIs;

program instructions that send the stream of verification data to the second storage system; and

program instructions that compare the stream of verification data with local data of the second storage system.