Live migration with pre-opened shared disks

Patent metadata

Field	Value
Publication number	US-9588796-B2
Application number	US-201414587980-A
Country	US
Kind code	B2
Filing date	Dec 31, 2014
Priority date	Jun 28, 2014
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

Examples perform live migration of virtual machines (VM) from a source host to a destination host. The live migration performs time-consuming operations before the source host is stunned, reducing the downtime apparent to users. Some examples contemplate pre-copying memory from the source VM to the destination VM, and the opening of disks on the destination VM before stunning the source VM.

First claim

We claim:

1. A method comprising:
receiving a request to perform a live migration of a source virtual machine (VM) on a source host to a destination VM on a destination host;
in response to the received request, downgrading a lock on at least one disk of the source VM from an exclusive mode to a non-exclusive mode;
opening the disk on the destination VM in the non-exclusive mode while the source VM is executing;
suspending execution of the source VM;
transferring a virtual device state of the source VM to the destination VM;
executing the destination VM;
closing the disk on the source VM; and
upgrading the lock on the disk by the destination VM from the non-exclusive mode to the exclusive mode.

2. The method of claim 1 , further comprising pre-copying memory from the source VM to the destination VM after downgrading the lock.

3. The method of claim 1 , further comprising restoring the virtual device state on the destination VM before executing the destination VM.

4. The method of claim 1 , wherein the destination VM issues input/output (I/O) commands to the disk only after closing the disk on the source VM.

5. The method of claim 1 , wherein suspending execution of the source VM occurs after a pre-defined duration of time has elapsed since the destination VM opened the disk in the non-exclusive mode.

6. The method of claim 1 , wherein opening the disk on the destination VM in the non-exclusive mode comprises communicating with a vendor provider managing the disk.

7. The method of claim 1 , wherein commands to the source VM while it is stunned are transmitted to the destination VM for execution after the live migration.

8. One or more non-transitory computer-readable storage media including computer-executable instructions that, when executed, cause at least one processor to perform live migration using shared disk locks by:
downgrading locks on one or more disks of a source virtual machine (VM) from an exclusive mode to a non-exclusive mode, wherein a destination VM opens the disks in non-exclusive mode while the source VM is executing;
suspending execution of the source VM;
transferring virtual memory of the source VM to the destination VM, wherein the destination VM begins execution after restoration of the virtual memory at the destination VM; and
closing the disks on the source VM, wherein the destination VM upgrades the locks from the non-exclusive mode to the exclusive mode.

9. The computer-readable storage media of claim 8 , wherein the computer-executable instructions further cause at least one processor to receive a request to perform a live migration of the source VM to a destination VM, and wherein downgrading comprises downgrading the locks in response to the received request.

10. The computer-readable storage media of claim 8 , wherein the computer-executable instructions further cause at least one processor to pre-copy memory from the source VM to the destination VM after downgrading the locks.

11. The computer-readable storage media of claim 8 , wherein the computer-executable instructions cause the at least one processor to suspend execution of the source VM after a pre-defined duration of time has elapsed since the destination VM opened the disks in the non-exclusive mode.

12. The computer-readable storage media of claim 8 , wherein the computer-executable instructions cause the at least one processor to send a message to the destination VM, after downgrading the locks, that multiwriter mode is available for the disks.

13. The computer-readable storage media of claim 8 , wherein the computer-executable instructions cause the at least one processor to calculate the time involved for live migration from the source VM to the destination VM.

14. The computer-readable storage media of claim 8 , wherein the computer-executable instructions cause the at least one processor to commence the process of live migration after a trigger.

15. A system for performing live migration with one or more shared disks, said system comprising:
a memory area associated with a computing device, said memory area storing a destination virtual machine (VM); and
a processor programmed to:
open, in a non-exclusive mode on the destination VM, one or more disks associated with a source VM while the source VM is executing;
execute the destination VM after receiving a virtual device state of the source VM; and
after the source VM closes the disks, change the disks from the non-exclusive mode to an exclusive mode.

16. The system of claim 15 , wherein the one or more disks are selected from a group consisting of a virtual volume, a virtual storage array, and a virtual storage area network.

17. The system of claim 15 , wherein the processor is programmed to open the one or more disks on the destination VM in a multiwriter lock mode.

18. The system of claim 15 , wherein the processor is further programmed to restore the virtual device state of the source VM on the destination VM.

19. The system of claim 15 , wherein the processor is further programmed to issue input/output (I/O) commands to the disks only after the source VM closes the disks.

20. The system of claim 15 , wherein the processor is programmed to execute the destination VM in response to receiving an acknowledgment from the source VM that execution of the source VM is terminating.

Assignees

• Vmware Inc

Inventors

• Tarasuk-Levin Gabriel
• Dirks Patrick William Penzias
• Rajagopal Haripriya
• Godbole Sujay Shrikant
• Uluski Derek

Classifications

• G06F3/0647

  Migration mechanisms · CPC title

• G06F2212/152

  Virtualized environment, e.g. logically partitioned system · CPC title

• G06F2009/4557

  Distribution of virtual machine instances; Migration and load balancing · CPC title

• G06F9/4856

  resumption being on a different machine, e.g. task migration, virtual machine migration (G06F9/5088 takes precedence) · CPC title

• G06F9/5088

  involving task migration · CPC title