CONFIRMING DATA CONSISTENCY IN A DATA STORAGE ENVIRONMENT

• US 20150169671A1
• Filed: 02/23/2015
• Published: 06/18/2015
• Est. Priority Date: 11/19/2012
• Status: Active Grant

• Current Assignee: Dell International LLC (Dell Technologies Inc.)
• Original Assignee: Compellent Technologies Incorporated (Dell Technologies Inc.)
• Inventors: Pittelko, Michael H.
• Granted Patent: US 9,384,232 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 16/137 Hash-based content-based indexing of textual data G06F16/31
• CPC Class Codes: G06F 16/178 Techniques for file synchronisation in file systems
• CPC Class Codes: G06F 16/2365 Ensuring data consistency and integrity
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 2201/82 Solving problems relating to consistency ensuring consistency in mirrored systems G06F11/2064
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46

Abstract

A method for confirming replicated data at a data site, including utilizing a hash function, computing a first hash value based on first data at a first data site and utilizing the same hash function, computing a second hash value based on second data at a second data site, wherein the first data had previously been replicated from the first data site to the second data site as the second data. The method also includes comparing the first and second hash values to determine whether the second data is a valid replication of the first data. In additional embodiments, the first data may be modified based on seed data prior to computing the first hash value and the second data may be modified based on the same seed data prior to computing the second hash value. The process can be repeated to increase reliability of the results.

Claims

1. A method for confirming the validity of replicated data at a data storage site, the method comprising:

a) utilizing a hash function, computing a first hash value based on first data at a first data storage site, the first hash value being smaller in size than the first data;

b) utilizing the same hash function, computing a second hash value based on second data at a second data storage site, the first data having been previously replicated from the first data storage site to the second data storage site as the second data, and the second hash value being smaller in size than the second data; and

c) comparing the first and second hash values to determine whether the second data is a valid replication of the first data, wherein a mismatch between the first and second hash values indicates that at least one of the first or second data storage sites includes invalid data.

2. The method of claim 1, wherein the first and second data storage sites are remotely connected by a network, and further comprising transmitting at least one of the first or second hash values via the network for comparing with the other of the first or second hash values.

3. The method of claim 2, further comprising transmitting the hash function via the network from at least one of the first or second data storage sites to the other of the first or second data storage sites for use by both first and second data storage sites.

4. The method of claim 2, further comprising providing a data structure storing a plurality of hash functions, each being available for use by the first and second data storage sites.

5. The method of claim 4, further comprising selecting the hash function from the data structure storing a plurality of hash functions for utilization in computing the first and second hash values.

6. The method of claim 2, further comprising modifying the first data based on seed data prior to computing the first hash value and modifying the second data based on the seed data prior to computing the second hash value.

8. The method of claim 6, further comprising transmitting the hash function and hash seed via the network from at least one of the first or second data storage sites to the other of the first or second data storage sites for use by both first and second data storage sites.

9. The method of claim 1, further comprising:

utilizing a second hash function, computing a third hash value based on the first data;

utilizing the second hash function, computing a fourth hash value based on the second data; and

comparing the third and fourth hash values to determine whether the second data is a valid replication of the first data.

10. The method of claim 6, further comprising:

modifying the first and second data based on second seed data;

utilizing the hash function, computing a third hash value based on the modified first data;

utilizing the second hash function, computing a fourth hash value based on the modified second data; and

comparing the third and fourth hash values to determine whether the second data is a valid replication of the first data.

11. The method of claim 1, further comprising repeating steps a) through c) a plurality of times, each time utilizing a different hash function than in a previous time.

12. The method of claim 11, wherein the steps a) through c) are repeated according to a predetermined periodic cycle.

7. The method of claim 7, further comprising transmitting the seed data via the network from at least one of the first or second data storage sites to the other of the first or second data storage sites for use by both first and second data storage sites.

13. An information handling system comprising:

a first data storage site configured to compute a first hash value based on first data stored at the first data storage site, utilizing a hash function; and

a second data storage site, comprising data replicated from the first data storage site, and configured to compute a second hash value based on second data stored at the second data storage site, utilizing the same hash function;

wherein at least one of the first data storage site and second data storage site is configured to transmit its computed hash value via a computer network to the other of the first data storage site and second data storage site for comparison of the first hash value with the second hash value to determine whether the second data is a valid replication of the first data, wherein a mismatch between the first and second hash values indicates that at least one of the first or second data storage sites includes invalid data.

14. The information handling system of claim 13, wherein the first data storage site and the second data storage site are remotely connected via the computer network.

16. The information handling system of claim 14, wherein the first data storage site is configured to modify the first data based on seed data prior to computing the first hash value and the second data storage site is configured to modify the second data based on the seed data prior to computing the second hash value.

15. (canceled)

17. A method for confirming the validity of replicated data at a data storage site, the method comprising:

a) utilizing a hash function, computing a first hash value based on a selected portion of first data at a first data storage site;

b) utilizing the same hash function, computing a second hash value based on a selected portion of second data at a second data storage site, the first data having been previously replicated from the first data storage site to the second data storage site as the second data, and the selected portion of second data corresponding to the selected portion of first data;

c) comparing the first and second hash values to determine whether the selected portion of second data is a valid replication of the selected portion of first data; and

d) repeating steps a) through c) a plurality of times, each time utilizing a different selected portion of the first data and corresponding selected portion of the second data than in a previous time, wherein a mismatch between the first and second hash values indicates that at least one of the first or second data storage sites includes invalid data.

18. The method of claim 17, wherein the first and second data storage sites are remotely connected by a network, and further comprising transmitting at least one of the first or second hash values via the network for comparing with the other of the first or second hash values.

19. The method of claim 18, further comprising transmitting the hash function via the network from at least one of the first or second data storage sites to the other of the first or second data storage sites for use by both first and second data storage sites.

20. The method of claim 17, wherein the steps a) through c) are repeated according to a predetermined periodic cycle, each subsequent repetition in contiguous chain of repetitions resulting in a match of the first and second hash values increasing the likelihood that the second data is a valid replication of the first data.