Live migration of virtual disks

Patent metadata

Field	Value
Publication number	US-9239689-B2
Application number	US-201313852598-A
Country	US
Kind code	B2
Filing date	Mar 28, 2013
Priority date	Mar 28, 2013
Publication date	Jan 19, 2016
Grant date	Jan 19, 2016

Abstract

A system and method are disclosed for live migration of a virtual disk of a virtual machine between storage devices. In accordance with one example, a computer system prepares a first area of a first storage device and a second area of a second storage device for a live snapshot of a virtual disk of a virtual machine. A transaction is then executed that comprises: storing the live snapshot in the first area of the first storage device, copying the live snapshot to the second area of the second storage device, and mirroring a change to the virtual disk that occurs after the creation of the live snapshot, where the mirroring is via one or more write operations to the live snapshot in the first area and to the copy of the live snapshot in the second area.

First claim

What is claimed is:

1. A method comprising:
preparing, by a processor, a first area of a first storage device and a second area of a second storage device for a live snapshot of a virtual disk of a virtual machine;
executing, after the preparing, a transaction that comprises:
storing the live snapshot in the first area of the first storage device;
copying the live snapshot to the second area of the second storage device; and
mirroring a change to the virtual disk that occurs after the live snapshot is created, wherein the mirroring is via one or more write operations to the live snapshot in the first area and to the copy of the live snapshot in the second area; and

changing, after the transaction executes successfully, the virtual disk of the virtual machine from the first area of the first storage device to the second area of the second storage device.

2. The method of claim 1 further comprising detecting a failure in at least one of the storing, the copying, or the mirroring.

3. The method of claim 2 further comprising deleting, in response to the detecting the failure, the live snapshot in the first area and the copy of the live snapshot in the second area.

4. The method of claim 2 further comprising rolling back, in response to the detecting the failure, the one or more write operations to the live snapshot in the first area and to the copy of the live snapshot in the second area.

5. The method of claim 1 wherein the preparing of the first area comprises allocating and initializing the area.

6. The method of claim 1 wherein the one or more write operations comprises a first write operation to the first area and a second write operation to the second area, and wherein the first write operation and the second write operation are concurrent.

7. The method of claim 1 wherein the copying and mirroring are executed concurrently.

8. The method of claim 1 wherein, prior to the preparing, the virtual disk is mapped to an area of the first storage device, and wherein the changing comprises mapping, after the transaction executes successfully, the virtual disk to the second area of the second storage device instead of to the area of the first storage device.

9. An apparatus comprising:
a memory to store a virtual machine comprising a virtual disk; and
a processor, operatively coupled to the memory, to:
prepare a first area of a first storage device and a second area of a second storage device for a live snapshot of the virtual disk;
execute, after the preparing, a transaction to:
store the live snapshot in the first area of the first storage device;
copy the live snapshot to the second area of the second storage device; and
mirror a change to the virtual disk via one or more write operations to the live snapshot in the first area and to the copy of the live snapshot in the second area; and

change, after the transaction executes successfully, the virtual disk of the virtual machine from the first area of the first storage device to the second area of the second storage device.

10. The apparatus of claim 9 wherein the processor is further to detect a failure in at least one of the storing, the copying, or the mirroring.

11. The apparatus of claim 10 wherein the processor is further to delete, in response to the detecting the failure, the live snapshot in the first area and the copy of the live snapshot in the second area.

12. The apparatus of claim 11 wherein the processor is further to roll back, in response to the detecting the failure, the one or more write operations to the live snapshot in the first area and to the copy of the live snapshot in the second area.

13. The apparatus of claim 9 wherein the preparing of the first area comprises allocating and initializing the area.

14. The apparatus of claim 9 wherein the one or more write operations comprises a first write operation to the first area and a second write operation to the second area, and wherein the first write operation and the second write operation are concurrent.

15. The apparatus of claim 9 wherein the copying and mirroring are executed concurrently.

16. The apparatus of claim 9 wherein, prior to the preparing, the virtual disk is mapped to an area of the first storage device, and wherein the processor is further to map the virtual disk to the second area of the second storage device instead of to the area of the first storage device after the transaction executes successfully.

17. A non-transitory computer readable storage medium, comprising instructions stored therein, which when executed, cause a processor to:
prepare, by a processor, a first area of a first storage device and a second area of a second storage device for a live snapshot of a virtual disk of a virtual machine;
execute, after the preparing, a transaction to:
store the live snapshot in the first area of the first storage device, copying the live snapshot to the second area of the second storage device; and
mirror a change to the virtual disk that occurs after the live snapshot is created,

wherein the mirroring is via one or more write operations to the live snapshot in the first area and to the copy of the live snapshot in the second area; and
change, after the transaction executes successfully, the virtual disk of the virtual machine from the first area of the first storage device to the second area of the second storage device.

18. The non-transitory computer readable storage medium of claim 17 wherein the instructions further cause the processor to detect a failure in at least one of the storing, the copying, or the mirroring.

19. The non-transitory computer readable storage medium of claim 18 wherein the instructions further cause the processor to delete, in response to the detecting the failure, the live snapshot in the first area and the copy of the live snapshot in the second area.

20. The non-transitory computer readable storage medium of claim 19 wherein the instructions further cause the processor to roll back, in response to the detecting the failure, the one or more write operations to the live snapshot in the first area and to the copy of the live snapshot in the second area.

Assignees

• Baron Ayal
• Simoncelli Federico
• Red Hat Israel Ltd

Inventors

• Baron Ayal
• Simoncelli Federico

Classifications

• G06F3/067

  Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS] · CPC title

• G06F3/0643

  Management of files · CPC title

• G06F3/0619 Primary

  in relation to data integrity, e.g. data losses, bit errors · CPC title

• G06F3/0631

  by allocating resources to storage systems · CPC title

• G06F3/0614

  Improving the reliability of storage systems · CPC title