System and method for verifying the consistency of mirrored data sets

• US 7,464,238 B1
• Filed: 04/28/2006
• Issued: 12/09/2008
• Est. Priority Date: 04/28/2006
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Inventors: Yadav, Vikas
• Primary Examiner(s): Verbrugge; Kevin
• Application Number:
  US11/414,051
• Time in Patent Office: 956 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
• 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 method for verifying consistency of one or more data sets located on a destination storage system with one or more data sets on a source storage system, comprising:

determining a common subset of data sets on the source and destination storage system;

initiating a data stream, for each data set of the common subset data sets, from the source storage system to the destination storage system; and

comparing the received data stream with one of the one or more data sets located on the destination storage system.

2. The method of claim 1 wherein the step of determining a common subset of data sets on the source and destination storage systems further comprises:

sending, from the destination storage system to the source storage system, a list of desired data sets; and

comparing, at the source storage system, the list of desired data sets with a list of local data sets to determine the common subset of data sets.

3. The method of claim 1 wherein the data stream comprises checksum information.

4. The method of claim 1 wherein the data stream comprises metadata information.

5. The method of claim 1 wherein the data sets comprise persistent consistency point images.

6. The method of claim 1 wherein the step of determining the common subset of data sets on the source and destination storage system further comprises:

sending, by the destination storage system to the source storage system, a list of data sets to be verified; and

identifying the common subset of data sets at the source storage system by comparing a list of data sets serviced by the source storage system with the list of data sets to be verified.

7. The method of claim 6 further comprising the step of locking the common subset of data sets on the source storage system.

8. The method of claim 7 further comprising the step of sending a list of the common subset of data sets to the destination storage system.

9. A system for verifying consistency of one or more data sets located on a destination storage system with one or more data sets located on a source storage system, the system comprising:

means for determining a common subset of data sets on the source and destination storage systems;

means for initiating a data stream, for each data set of the common subset of data sets, from the source storage system to the destination storage system; and

means for comparing the received data stream with one of the one or more located on the destination storage system.

10. The system of claim 9 wherein the means for determining a common subset of data sets on the source and destination storage system further comprises:

means for sending, from the destination storage system to the source storage system, a list of desired data sets; and

means for comparing, at the source storage system, the list of data sets with a list of local data sets to determine the common subset of data sets.

11. The system of claim 9 wherein the data stream comprises checksum information.

12. The system of claim 9 wherein the data stream comprises metadata information.

13. The system of claim 9 wherein the data sets comprise persistent consistency point images.

14. The system of claim 9 wherein the means for determining the common subset of data sets on the source and destination storage system further comprises:

means for sending, by the destination storage system to the source storage system, a list of data sets to be verified; and

means for identifying the common subset of data sets at the source storage system by comparing a list of data sets serviced by the source storage system with the list of data sets to be verified.

15. The system of claim 14 further comprising means for locking the common subset of data sets on the source storage system.

16. The system of claim 15 further comprising means for sending a list of the common subset of data sets to the destination storage system.

17. A computer readable medium for verifying consistency of one or more data sets located on a destination with one or more data sets located on a source, the computer readable medium including program instructions for performing the steps of:

determining a common subset of data sets on the source and destination;

initiating a data stream, for each data set of the common subset data sets, from the source to the destination; and

comparing the received data stream with one of the one or more data sets located on the destination.

18. The computer readable medium of claim 17 wherein the step of determining the common subset of data sets on the source and destination storage system further comprises the steps of:

sending, by the destination storage system to the source storage system, a list of data sets to be verified; and

identifying the common subset of data sets at the source storage system by comparing a list of data sets serviced by the source storage system with the list of data sets to be verified.

19. A system for verifying consistency of one or more data sets, the system comprising:

a source storage system having one or more local data sets, the source storage system executing a verification daemon;

a destination storage system executing a verification module;

wherein the verification module is adapted to compare a data stream generated by the verification daemon with a data set on the destination storage system.

20. The system of claim 19 wherein the data sets comprise persistent consistency point images.

21. The system of claim 19 wherein the verification module is adapted to transmit a list of desired data sets to the verification daemon and wherein the verification daemon is adapted to identify a common subset of data sets.

22. The system of claim 19 wherein the data stream generated by the verification daemon comprises checksum information.

23. The system of claim 19 wherein the verification module is further adapted to alert an administrator of an inconsistency between the data stream generated by the verification daemon and the data set on the destination storage system.

24. The system of claim 19 wherein the verification module and verification daemon are adapted to enable a plurality of data sets to be verified in parallel.

25. The system of claim 19 wherein the data stream comprises of checksum information associated with the data sets.

26. The system of claim 19 wherein the data stream comprises of metadata information associated with the data sets.

27. The system of claim 19 wherein the data stream comprises of data contained in the data sets.