Confirming data consistency in a data storage environment

• US 9,384,232 B2
• Filed: 02/23/2015
• Issued: 07/05/2016
• Est. Priority Date: 11/19/2012
• Status: Active Grant

• Current Assignee: Dell International LLC (Dell Technologies Inc.)
• Original Assignee: Dell International LLC (Dell Technologies Inc.)
• Inventors: Pittelko, Michael H.
• Primary Examiner(s): Syed, Farhan
• Application Number:
  US14/628,851
• Publication Number:
  US 20150169671A1
• Time in Patent Office: 498 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
• 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 validity of replicated data at a data storage site, the method comprising:

a) replicating first data from a first computer readable storage medium at a first data storage site as second data to a second computer readable storage medium at a second data storage site;

b) transmitting a hash function, executable by a computer processor, and a hash seed via a 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 so that the hash function and hash seed are available for use by both first and second data storage sites;

c) modifying the first data stored on the first computer readable storage medium at the first data storage site based on the hash seed, and utilizing the hash function, computing a first hash value based on the seed-modified first data, the first hash value being smaller in size than the first data;

d) modifying the second data stored on the second computer readable storage medium at the second data storage site based on the hash seed, and utilizing the hash function, computing a second hash value based on the seed-modified second data, the second hash value being smaller in size than the second data;

e) transmitting at least one of the first or second hash values via a computer network for comparing with the other of the first or second hash values, instead of transmitting the larger sized first or second data via the computer network; and

f) comparing the first and second hash values, in lieu of comparing the actual first and second data, 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 the computer network.

3. The method of claim 1, further comprising providing a data structure storing a plurality of hash functions executable by a computer processor, each being available for use by the first and second data storage sites.

4. The method of claim 3, 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.

5. The method of claim 1, further comprising:

utilizing a second hash function executable by a computer processor, computing a third hash value based on the first data stored on the first computer readable storage medium at the first data storage site;

utilizing the second hash function, computing a fourth hash value based on the second data stored on the second computer readable storage medium at the second data storage site;

transmitting at least one of the third or fourth hash values via a computer network for comparing with the other of the third or fourth hash values; and

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

6. The method of claim 1, further comprising:

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

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

utilizing the hash function, computing a fourth hash value based on the second hash seed-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.

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

8. The method of claim 7, wherein the steps b) through e) are repeated according to a predetermined periodic cycle.

9. An information handling system comprising:

a first data storage site comprising a computer readable storage medium storing first data, and a computer processor computing a first hash value based on the first data and a hash seed, utilizing a hash function; and

a second data storage site comprising a computer readable storage medium storing data replicated from the first data storage site and a computer processor computing a second hash value based on second data and a hash seed, utilizing the same hash function;

wherein at least one of the first data storage site and second data storage site is configured to transmit the hash function and hash seed via a computer network to the other of the first data storage site or second data storage site so that the hash function and hash seed are available for use by both first and second data storage sites; and

wherein at least one of the first data storage site and second data storage site is configured to transmit its computed hash value via the 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, in lieu of comparing the actual first and second data, 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.

10. The information handling system of claim 9, wherein the first data storage site and the second data storage site are remotely connected via the computer network.

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

a) replicating first data from a first computer readable storage medium at a first data storage site as second data to a second computer readable storage medium at a second data storage site;

b) transmitting a hash function, executable by a computer processor, and a hash seed via a 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 so that the hash function and hash seed are available for use by both first and second data storage sites;

c) modifying a selected portion of the first data stored on the first computer readable storage medium at the first data storage site based on the hash seed, and utilizing the hash function, computing a first hash value based on the seed-modified selected portion of the first data;

d) modifying a selected portion of the second data stored on the second computer readable storage medium at the second data storage site based on the hash seed, and utilizing the hash function, computing a second hash value based on the seed-modified selected portion of the second data, the selected portion of the second data corresponding to the selected portion of the first data;

e) transmitting at least one of the first or second hash values via a computer network for comparing with the other of the first or second hash values, instead of transmitting the larger sized first or second data via the computer network;

f) comparing the first and second hash values, in lieu of comparing the actual first and second data, to determine whether the selected portion of second data is a valid replication of the selected portion of first data; and

f) repeating steps c) through f) 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.

12. The method of claim 11, wherein the first and second data storage sites are remotely connected by the network.

13. The method of claim 11, wherein the steps c) through f) 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.