Confirming data consistency in a data storage environment

• US 9,002,792 B2
• Filed: 11/19/2012
• Issued: 04/07/2015
• 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.
• Primary Examiner(s): SYED, FARHAN M
• Application Number:
  US13/680,265
• Publication Number:
  US 20140143206A1
• Time in Patent Office: 869 Days
• US Class Current: 707/634
• 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 in the form of a computer algorithm executable by a computer processor, computing a first hash value based on first data stored on a computer readable storage medium at a first data storage site, the first hash value being in a digital format suitable for transmission over a computer network and being smaller in electronic data transmission size than the first data;

b) utilizing the same hash function, computing a second hash value based on second data stored on a computer readable storage medium at a second data storage site remotely connected by a computer network with the first data storage site, the first data having been previously replicated over the computer network from the first data storage site to the second data storage site as the second data, and the second hash value being in a digital format suitable for transmission over a computer network and being smaller in electronic data transmission size than the second data;

c) transmitting at least one of the first or second hash values via the computer network for comparing with the other of the first or second hash values;

d) digitally comparing the first and second hash values to determine the likelihood as to whether the second data is a valid replication of the first data;

e) utilizing a second hash function in the form of a computer algorithm executable by a computer processor, computing a third hash value based on the first data, the third hash value being in a digital format suitable for transmission over a computer network and being smaller in electronic data transmission size than the first data;

f) utilizing the second hash function, computing a fourth hash value based on the second data, the fourth hash value being in a digital format suitable for transmission over a computer network and being smaller in electronic data transmission size than the second data; and

g) digitally comparing the third and fourth hash values to determine the likelihood as to whether the second data is a valid replication of the first data;

wherein a mismatch between the first and second hash values or between the third and fourth hash values indicates that at least one of the first or second data storage sites includes invalid data.

2. The method of claim 1, further comprising transmitting the hash function via the computer 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.

3. The method of claim 1, further comprising providing a computer readable data storage structure storing a plurality of hash functions in the form of computer algorithms executable by a computer processing unit, each hash function being available for use, and electronically accessible, by the first and second data storage sites.

4. The method of claim 3, further comprising selecting the hash function from the computer readable data storage structure storing a plurality of hash functions for utilization in computing the first and second hash values.

5. The method of claim 1, 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 same seed data prior to computing the second hash value.

6. The method of claim 5, further comprising transmitting the seed data via the computer 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.

7. The method of claim 5, further comprising transmitting the hash function and hash seed via the computer 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.

8. The method of claim 5, further comprising modifying the first data based on the seed data prior to computing the third hash value and modifying the second data based on the seed data prior to computing the fourth hash value.

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

10. The method of claim 9, wherein the steps a) through d) are repeated according to a predetermined periodic cycle.

16. The method of claim 5, wherein the seed data is a function, in the form of a computer algorithm executable by a computer processing unit, for modifying data input to the function and outputting modified data.

11. An information handling system comprising:

a first data storage site comprising a computer readable storage medium and a computer processor, the first data storage site computing;

a first hash value based on first data stored on the computer readable storage medium at the first data storage site, utilizing a first hash function in the form of a computer algorithm executable by the computer processor, the first hash value being in a digital format suitable for transmission over a computer network and being smaller in electronic data transmission size than the first data; and

a second hash value based on the first data, utilizing a second hash function in the form of a computer algorithm executable by a computer processor, the second hash value being in a digital format suitable for transmission over a computer network and being smaller in electronic data transmission size than the first data; and

a second data storage site remotely connected by a computer network with the first data storage site and comprising data replicated over the computer network from the first data storage site, the second data storage site computing;

a third hash value based on second data stored on a computer readable storage medium at the second data storage site, utilizing the first hash function, the third hash value being in a digital format suitable for transmission over a computer network and being smaller in electronic data transmission size than the second data; and

a fourth hash value based on the second data, utilizing the second hash function, the fourth hash value being in a digital format suitable for transmission over a computer network and being smaller in electronic data transmission size than the second data;

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

12. The information handling system of claim 11, 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 same seed data prior to computing the third hash value.

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

a) utilizing a hash function in the form of a computer algorithm executable by a computer processor, computing a first hash value based on a selected portion of first data stored on a computer readable storage medium at a first data storage site, the first hash value being in a digital format suitable for transmission over a computer network and being smaller in electronic data transmission size than the selected portion of first data;

b) utilizing the same hash function, computing a second hash value based on a selected portion of second data stored on a computer readable storage medium at a second data storage site remotely connected by a computer network with the first data storage site, the first data having been previously replicated over the computer network from the first data storage site to the second data storage site as the second data, the selected portion of second data corresponding to the selected portion of first data, and the second hash value being in a digital format suitable for transmission over a computer network and being smaller in electronic data transmission size than the selected portion of second data;

c) transmitting at least one of the first or second hash values via the computer network for comparing with the other of the first or second hash values;

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

e) repeating steps a) through d) 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, the results substantially representative of the likelihood as to whether the second data as a whole is a valid replication of the first data as a whole.

14. The method of claim 13, further comprising transmitting the hash function via the computer 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.

15. The method of claim 13, wherein in step e), the steps a) through d) are repeated according to a predetermined periodic cycle, each subsequent repetition in a 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.