Four site data replication using host based active/active model

• US 9,811,272 B1
• Filed: 12/28/2011
• Issued: 11/07/2017
• Est. Priority Date: 12/28/2011
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Inventors: Lecrone, Douglas E., Egan, Michael John, Quinn, Brett A.
• Primary Examiner(s): Perez-Velez, Rocio Del Mar
• Application Number:
  US13/338,719
• Time in Patent Office: 2,141 Days
• CPC Class Codes: G06F 11/2058 using more than 2 mirrored copies
• CPC Class Codes: G06F 11/2064 while ensuring consistency
• CPC Class Codes: G06F 11/2069 Management of state, configuration or failover
• CPC Class Codes: G06F 11/2074 Asynchronous techniques
• CPC Class Codes: G06F 11/2076 Synchronous techniques
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

A system and method for data replication is provided. A host synchronously replicates data between a first local storage device and a second local storage device, the first local storage device and the second local storage device being coupled to the host. Data is then asynchronously replicated from the first local storage device and the second local storage device to at least one remote storage device. In an embodiment, each of the local storage devices may asynchronously replicate data to remote storage devices located at separate sites to provide four site data replication processing. The system described herein provides for advantageous and efficient swapping of control between hosts and storage devices located in different regions in response to disasters and/or other events affecting data storage in a particular region.

Claims

1. A method for data replication, comprising:

using a first host to write a first set of data to a first storage device coupled to the first host;

using the first host to replicate the first set of data to a second storage device coupled to the first host, wherein the first host synchronously replicates the first set of data to the second storage device separately from writing the first set of data to the first storage device using a link between the first host and the second storage device that does not include the first storage device;

using a second host to write a second set of data to the second storage device coupled to the second host;

using the second host to replicate the second set of data to the first storage device coupled to the second host, wherein the second host synchronously replicates the second set of data to the first storage device separately from writing the second set of data to the second storage device using a link between the second host and the first storage device that does not include the second storage device; and

replicating the first and the second sets of data from each of the first storage device and the second storage device to at least one other storage device located remotely from the first and second storage devices, wherein the first storage device is located at a different site than the second storage device, and wherein the at least one remote storage device includes a third storage device and a fourth storage device located at different remote sites that receive the first and the second sets of data from the first and second storage devices, respectively, the first and the second sets of data being asynchronously replicated from the first storage device to the third storage device and asynchronously replicated from the second storage device to the fourth storage device, the third storage device and the fourth storage device passively receiving the first and the second sets of data.

2. The method of claim 1, wherein the asynchronous data replication between the first storage device and the at least one other storage device is completed at a different time than the asynchronous data replication between the second storage device and the at least one other storage device.

3. The method of claim 1, further comprising:

swapping operational control from the first and second hosts to at least one other host for the third storage device and the fourth storage device, wherein the at least one other host synchronously replicates data between the third storage device and the fourth storage device, the third storage device and the fourth storage device being coupled to the at least one other host, and wherein the data from the third storage device and the fourth storage device is replicated to the first storage device and the second storage device, respectively.

4. A non-transitory computer readable medium storing software for data replication, the software comprising:

executable code that, using a first host, writes a first set of data to a first storage device coupled to the first host;

executable code that, using the first host, replicates the first set of data to a second storage device coupled to the first host, wherein the first host synchronously replicates the data to the second storage device separately from writing the first set of data to the first storage device using a link between the first host and the second storage device that does not include the first storage device;

executable code that, using a second host, writes a second set of data to the second storage device coupled to the second host;

executable code that, using the second host, replicates the second set of data to the first storage device coupled to the second host, wherein the second host synchronously replicates the second set of data to the first storage device separately from writing the second set of data to the second storage device using a link between the second host and the first storage device that does not include the second storage device; and

executable code that replicates the first and the second sets of data from each of the first storage device and the second storage device to at least one other storage device located remotely from the first and second storage devices, wherein the first storage device is located at a different site than the second storage device, and wherein the at least one other storage device includes a third storage device and a fourth storage device located at different remote sites that receive the first and the second sets of data from the first and second storage devices, respectively, the first and the second sets of data being asynchronously replicated from the first storage device to the third storage device and asynchronously replicated from the second storage device to the fourth storage device, the third storage device and the fourth storage device passively receiving the first and the second sets of data.

5. The non-transitory computer readable medium of claim 4, wherein the asynchronous data replication between the first storage device and the at least one other storage device is completed at a different time than the asynchronous data replication between the second storage device and the at least one other storage device.

6. The non-transitory computer readable medium of claim 4, further comprising:

executable code that swaps operational control from the first and second hosts to at least one other host for the third storage device and the fourth storage device, wherein the at least one other host synchronously replicates data between the third storage device and the fourth storage device, the third storage device and the fourth storage device being coupled to the at least one other host, and wherein the data from the third storage device and the fourth storage device is asynchronously replicated to the first storage device and the second storage device, respectively.

7. A system for performing data replication, comprising:

a first storage device;

a second storage device;

a first host coupled to the first storage device and coupled to the second storage device using a first link between the first host and the second storage device that does not include the first storage device, wherein the first host uses the first link to synchronously replicate a first set of data to the second storage device that is initially written to the first storage device by the first host prior to being replicated to the second storage device;

a second host coupled to the first storage device and coupled to the second storage device using a second link between the second host and the first storage device that does not include the second storage device, wherein the second host uses the second link to synchronously replicate a second set of data to the first storage device that is initially written to the second storage device by the second host prior to being replicated to the first storage device;

a third storage device coupled to the first storage device; and

a fourth storage device coupled to the second storage device, wherein the first and the second sets of data are asynchronously replicated from the first storage device to the third storage device and asynchronously replicated from the second storage device to the fourth storage device, the third storage device and the fourth storage device passively receiving the first and the second sets of data.

8. The system of claim 7, wherein the first storage device is located at a different site than the second storage device, and wherein the third storage device and the fourth storage device are located at different remote sites.

9. The system of claim 7, wherein the asynchronous data replication between the first storage device and the third storage device is completed at a different time than the asynchronous data replication between the second storage device and the fourth storage device.

10. The system of claim 7, further comprising:

a non-transitory computer readable medium executable by at least one processor of the system, the non-transitory computer readable medium including;

executable code that swaps operational control from the first and second hosts to at least one other host for the third storage device and the fourth storage device, wherein the at least one other host synchronously replicates data between the third storage device and the fourth storage device, the third storage device and the fourth storage device being coupled to the at least one other host, and wherein the data from the third storage device and the fourth storage device is replicated to the first storage device and the second storage device, respectively.