REDUCING DATA AMPLIFICATION WHEN REPLICATING OBJECTS ACROSS DIFFERENT SITES

• US 20190034087A1
• Filed: 07/26/2017
• Published: 01/31/2019
• Est. Priority Date: 07/26/2017
• Status: Active Grant

• Current Assignee: Vmware LLC (Broadcom, Inc.)
• Original Assignee: VMware, Inc. (Broadcom, Inc.)
• Inventors: RENAULD, Pascal, XIANG, Enning, KNAUFT, Eric
• Granted Patent: US 10,871,911 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/2058 using more than 2 mirrored copies
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• 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 2009/45579 I/O management, e.g. providing access to device drivers or storage
• CPC Class Codes: G06F 2009/45583 Memory management, e.g. access or allocation
• CPC Class Codes: G06F 2009/45595 Network integration; Enabling network access in virtual machine instances
• CPC Class Codes: G06F 2201/815 Virtual
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects

Abstract

Component objects of a virtual disk are backed by first storage nodes, which are at a primary site, and replicated in second storage nodes, which are at a secondary site. Responsive to a write command issued to the virtual disk, a coordinating node at the primary site issues a first write operation to a first replication module running therein, and transmits a second write operation to a second replication module running in a coordinating node at the secondary site. The first replication module, responsive to the first write operation, instructs the first storage nodes backing first and second component objects of the virtual disk to write the data. The second replication module, responsive to the second write operation, instructs the second storage nodes backing third and fourth component objects, which are replicas of the first and second component objects, respectively, to write the data.

Claims

1. A method of replicating component objects of a virtual disk, that are backed by first storage nodes, which are at a primary site, in second storage nodes, which are at a secondary site, said method comprising:

at a coordinating node at the primary site, responsive to a write command issued to the virtual disk, issuing a first write operation, transmitting a second write operation, identical to the first write operation, to a coordinating node at the secondary site, and instructing, responsive to the first write operation, the first storage nodes that are backing first and second component objects of the virtual disk to write data in their corresponding local storage devices, wherein

the coordinating node at the secondary site, responsive to the second write operation, instructs the second storage nodes that are backing third and fourth component objects to write data in their corresponding local storage devices.

2. The method of claim 1, wherein the data written in the local storage devices of the first storage nodes are identical to the data written in the local storage devices of the second storage nodes.

3. The method of claim 2, wherein the data written in the local storage devices of each of the first storage nodes are identical, and the data written in the local storage devices of each of the second storage nodes are identical.

4. The method of claim 2, wherein the data written in the local storage devices of the first storage nodes include first data, which is written in the local storage devices of one of the first storage nodes, and second data, which is written in the local storage devices of another one of the first storage nodes, and the data written in the local storage devices of the second storage nodes include the first data and the second data, the first data being written in the local storage devices of one of the second storage nodes and the second data being written in the local storage devices of another one of the second storage nodes.

5. The method of claim 4, wherein the first data is user data and the second data is parity data.

6. The method of claim 1, wherein the instructing by the coordinating nodes at the primary and the secondary sites are performed by their respective RAID 1 engines.

7. The method of claim 1, wherein the instructing by the coordinating nodes at the primary and the secondary sites are performed by their respective RAID 5 engines.

8. The method of claim 1, wherein the coordinating node at the primary site further includes a third replication module that issues the first and second write operations.

9. A non-transitory computer readable medium comprising instructions to be executed in a coordinating node at a primary site to carry out a method of replicating component objects of a virtual disk, that are backed by first storage nodes, which are at the primary site, in second storage nodes, which are at a secondary site, said method comprising:

responsive to a write command issued to the virtual disk, issuing a first write operation, transmitting a second write operation, identical to the first write operation, to a coordinating node at the secondary site, and instructing, responsive to the first write operation, the first storage nodes that are backing first and second component objects of the virtual disk to write data in their corresponding local storage devices, wherein

the coordinating node at the secondary site, responsive to the second write operation, instructs the second storage nodes that are backing third and fourth component objects to write data in their corresponding local storage devices.

10. The non-transitory computer readable medium of claim 9, wherein the data written in the local storage devices of the first storage nodes are identical to the data written in the local storage devices of the second storage nodes.

11. The non-transitory computer readable medium of claim 10, wherein the data written in the local storage devices of each of the first storage nodes are identical, and the data written in the local storage devices of each of the second storage nodes are identical.

12. The non-transitory computer readable medium of claim 10, wherein the data written in the local storage devices of the first storage nodes include first data, which is written in the local storage devices of one of the first storage nodes, and second data, which is written in the local storage devices of another one of the first storage nodes, and the data written in the local storage devices of the second storage nodes include the first data and the second data, the first data being written in the local storage devices of one of the second storage nodes and the second data being written in the local storage devices of another one of the second storage nodes.

13. The non-transitory computer readable medium of claim 12, wherein the first data is user data and the second data is parity data.

14. The non-transitory computer readable medium of claim 9, wherein the instructing by the coordinating nodes at the primary and the secondary sites are performed by their respective RAID 1 engines.

15. The non-transitory computer readable medium of claim 9, wherein the instructing by the coordinating nodes at the primary and the secondary sites are performed by their respective RAID 5 engines.

16. The non-transitory computer readable medium of claim 9, wherein the coordinating node at the primary site further includes a third replication module that issues the first and second write operations.

17. A distributed computer system for replicating first and second component objects of a virtual disk, comprising:

a first coordinating node;

first storage nodes that back the first and second component objects, the first storage nodes communicating with the first coordinating node through a first local area network;

a second coordinating node communicating with the first coordinating node through a wide area network; and

second storage nodes that back third and fourth component objects, which are replicas of the first and second component objects, respectively, the second storage nodes communicating with the second coordinating node through a second local area network, wherein

responsive to a write command issued to the virtual disk, the first coordinating node issues a first write operation , transmits a second write operation, identical to the first write operation, to the second coordinating node, and instructs, responsive to the first write operation, the first storage nodes that are backing the first and second component objects to write data in their corresponding local storage devices, wherein

the coordinating node at the secondary site, responsive to the second write operation, instructs the second storage nodes that are backing the third and fourth component objects to write data in their corresponding local storage devices.

18. The distributed computer system of claim 17, wherein the instructing by the coordinating nodes at the primary and the secondary sites are performed by their respective RAID 1 engines.

19. The distributed computer system of claim 17, wherein the instructing by the coordinating nodes at the primary and the secondary sites are performed by their respective RAID 5 engines.

20. The distributed computer system of claim 17, wherein the first coordinating node further includes a RAID 1 engine that issues the first and second write operations.