System and method for using local storage to emulate centralized storage

• US 9,454,446 B2
• Filed: 01/04/2013
• Issued: 09/27/2016
• Est. Priority Date: 07/21/2009
• Status: Active Grant

• Current Assignee: Vmware LLC (Broadcom, Inc.)
• Original Assignee: VMware, Inc. (Broadcom, Inc.)
• Inventors: Hansen, Jacob Gorm
• Primary Examiner(s): Nguyen, Loan T
• Application Number:
  US13/734,186
• Publication Number:
  US 20130125122A1
• Time in Patent Office: 1,362 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1484 involving virtual machines
• CPC Class Codes: G06F 11/2025 using centralised failover control functionality
• CPC Class Codes: G06F 11/2041 with more than one idle spare processing component
• CPC Class Codes: G06F 11/2048 where the redundant components share neither address space nor persistent storage
• CPC Class Codes: G06F 11/2097 maintaining the standby controller/processing unit updated initialisation or re-synchronisation thereof G06F11/1658 and subgroups
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 16/178 Techniques for file synchronisation in file systems
• CPC Class Codes: G06F 16/188 Virtual file systems
• CPC Class Codes: G06F 16/20 of structured data, e.g. relational data
• CPC Class Codes: G06F 16/23 Updating
• 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 9/45558 Hypervisor-specific management and integration aspects

Abstract

Methods and systems for utilizing local storage of host computers to emulate a centralized storage system comprise receiving a write operation from a virtual machine running on a first host computer, wherein the write operation corresponds to a disk image that is locally stored in a first host computer. The disk image and a second disk image is updated in accordance with the write operation, wherein (i) the second disk image is locally stored on a second host computer that is networked to the first host computer, (ii) the second disk image serves as a back-up to the disk image, and (ii) the second host computer is configured to support the running of other virtual machines that access other disks images that (a) are locally stored on the second host computer, and (b) are further backed-up on at least a third host computer.

Claims

1. A host computer configured to emulate accessing a centralized storage system, the host computer comprising:

a first local storage unit for storing a first disk image;

one or more computer processors; and

a non-transitory computer-readable storage medium comprising instructions for controlling the one or more computer processors to be configured for;

receiving a write operation from a virtual machine running on the host computer, wherein the write operation is directed to a virtual address in a virtual address space for the virtual machine, and

in response to receiving the write operation directed to the virtual address, updating the first disk image at a first physical address corresponding to the virtual address and a second disk image at a second physical address different from the first physical address, wherein the second physical address also corresponds to the virtual address, and wherein (i) the second disk image is stored on second local storage of a second host computer that is networked to the host computer, (ii) the second disk images serves as a back-up to the first disk image on the host computer, and (iii) the second host computer is supporting the running of a first set of other virtual machines that access a third set of disks images that (a) are locally stored on the second local storage of the second host computer along with the second disk image, and (b) are further backed-up on a fourth set of disk images locally stored on third local storage of at least a third host computer that is supporting the running of a second set of other virtual machines.

2. The host computer of claim 1, wherein the third host computer is the same as the host computer.

3. The host computer of claim 1, wherein the third host computer is different from first host computer.

4. The host computer of claim 1, wherein, upon a failure of the host computer, the second host computer instantiates a virtual machine using the second disk image stored on the second local storage of the second host computer.

5. The host computer of claim 1, wherein the second disk image is formatted as a log file of updates made to the first disk image as a result of write operations made by the virtual machine to the first disk image.

6. The host computer of claim 1, wherein the receiving and updating the first disk image steps are performed by a hypervisor of the host computer.

7. The host computer of claim 1, wherein the receiving and updating of the first disk image steps are performed by a file system component of the hypervisor.

8. A method for utilizing local storage of host computers to emulate a centralized storage system, the method comprising:

receiving a write operation from a virtual machine running on the host computer, wherein the write operation is directed to a virtual address in a virtual address space for the virtual machine that is stored on a first local storage in the first host computer; and

in response to receiving the write operation directed to the virtual address, updating a first disk image at a first physical address corresponding to the virtual address on a first local storage in the first host computer and a second disk image at a second physical address different from the first physical address, wherein the second physical address also corresponds to the virtual address, wherein (i) the second disk image is stored on a second local storage of a second host computer that is networked to the host computer, (i) the second disk image serves as a back-up to the first disk image on the host computer, and (iii) the second host computer is supporting the running of a first set of other virtual machines that access a third set of disks images that (a) are locally stored on the second local storage of the second host computer along with the second disk image, and (b) are further backed-up on a fourth set of disk images locally stored on a third local storage of at least a third host computer that is supporting the running of a second set of other virtual machines.

9. The method of claim 8, wherein the third host computer is the same as the first host computer.

10. The method of claim 8, wherein the third host computer is different from the first host computer.

11. The method of claim 8, wherein, upon a failure of the first host computer, the second host computer instantiates a virtual machine using the second disk image stored on the local storage of the second host computer.

12. The method of claim 8, wherein the second disk image is formatted as a log file of updates made to the first disk image as a result of write operations made by the virtual machine to the first disk image.

13. The method of claim 8, performed by a hypervisor of the first host computer.

14. The method of claim 13, performed by a file system component of the hypervisor.

15. A non-transitory computer-readable storage medium including instructions that, when executed by a processing unit of a first host computer causes the processing unit to utilize a first local storage in the first host computer to emulate a centralized storage system by performing the steps of:

receiving a write operation from a virtual machine running on the host computer, wherein the write operation is directed to a virtual address in a virtual address space for the virtual machine that is stored on a first local storage in the first host computer; and

in response to receiving the write operation directed to the virtual address, updating a first disk image at a first physical address corresponding to the virtual address in a first local storage in the first host computer and a second disk image at a second physical address different from the first physical address, wherein the second physical address also corresponds to the virtual address, wherein (i) the second disk image is stored on a second local storage of a second host computer that is networked to the host computer, (ii) the second disk computer is supporting the running of a first set of other virtual machines that access a third set of disks images that (a) are locally stored on the second local storage of the second host computer along with the second disk image, and (b) are further backed-up on a fourth set of disk images locally stored on third local storage of at least a third host computer that is supporting the running of a second set of other virtual machines.

16. The non-transitory computer-readable storage of claim 15, wherein the third host computer is the same as the first host computer.

17. The non-transitory computer-readable storage of claim 15, wherein the third host computer is different from the first host computer.

18. The non-transitory computer-readable storage of claim 15, wherein, upon a failure of the first host computer, the second host computer instantiates a virtual machine using the second disk image stored on the second local storage of the second host computer.

19. The non-transitory computer-readable storage of claim 15, wherein the second disk image is formatted as a log file of updates made to the first disk image as a result of write operations made by the virtual machine to the disk image.

20. The non-transitory computer-readable storage of claim 15, wherein the steps are performed by a hypervisor of the first host computer.