VIRTUAL MACHINE MEMORY MIGRATION BY STORAGE

• US 20140215459A1
• Filed: 01/29/2013
• Published: 07/31/2014
• Est. Priority Date: 01/29/2013
• Status: Active Grant

• Current Assignee: Red Hat Israel Ltd. (International Business Machines Corporation)
• Original Assignee: Red Hat Israel Ltd. (International Business Machines Corporation)
• Inventors: Tsirkin, Michael
• Granted Patent: US 10,241,814 B2
• Time in Patent Office: Days
• US Class Current: 718/1
• CPC Class Codes: G06F 2009/4557 Distribution of virtual machine instances; Migration and load balancing
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects

Abstract

Systems and methods for live migration are provided. A hypervisor receives a request to migrate a virtual machine from a source host machine to a destination host machine, and maps memory of the virtual machine on the source host machine to a storage device accessible by the source host machine and by the destination host machine.

Claims

1. A method, comprising:

receiving a request to migrate a virtual machine from a source host machine to a destination host machine; and

mapping, by a hypervisor, memory of the virtual machine on the source host machine on a storage device, wherein the storage device is accessible by the source host machine and by the destination host machine.

2. The method of claim 1 further comprising:

caching at least a portion of memory of the virtual machine in a cache on the source host machine;

detecting a state of the memory of the virtual machine using the cache on the source host machine and the mapped memory on the storage device; and

issuing a command to stop the virtual machine on the source host machine when a change in the state of the memory of the virtual machine is below a threshold.

3. The method of claim 2, wherein detecting the state of the memory of the virtual machine comprises:

measuring an amount of existing data on the cache on the source host machine.

4. The method of claim 3, wherein detecting the state of the memory of the virtual machine further comprises:

issuing a command to synchronize the data on the cache; and

measuring an amount of time to synchronize the cache.

5. The method of claim 2 further comprising:

estimating an amount of downtime during a virtual machine migration based on at least one of;

a time to synchronize the mapped memory of the virtual machine with the cache, or an amount of data stored on the cache.

6. The method of claim 1, wherein the storage device and the destination host machine are part of the same network.

7. The method of claim 1, wherein the memory of the virtual machine on the source host machine is mapped on the storage device on system boot.

8. The method of claim 2 further comprising:

transmitting a remaining portion of the state of the virtual machine from the source host machine to the destination host machine.

9. The method of claim 8 wherein the remaining state of the virtual machine comprises at least one of:

a CPU register, a register of a network card exposed to the virtual machine, or a device accessible to the virtual machine.

10. A system, comprising:

a memory; and

a processing device, coupled with the memory, to;

receive a request to migrate a virtual machine from a source host machine to a destination host machine; and

map memory of the virtual machine on the source host machine on a storage device, wherein the storage device is accessible by the source host machine and by the destination host machine.

11. The system of claim 10, the processing device further to:

cache at least a portion of memory of the virtual machine in a cache on the source host machine.

detect a state of the memory of the virtual machine using the cache on the source host machine and the mapped memory on the storage device, and

issue a command to stop the virtual machine on the source host machine when a change in the state of the memory of the virtual machine is below a threshold.

12. The system of claim 11, wherein when detecting the state of the memory of the virtual machine, the processing device to:

measure an amount of existing data on the cache on the source host machine.

13. The system of claim 12, wherein when detecting the state of the memory of the virtual machine, the processing device further to:

issue a command to synchronize the data on the cache;

measure an amount of time to synchronize the cache.

14. The system of claim 11, the processing device further to:

estimate an amount of downtime during a virtual machine migration based on at least one of;

a time to synchronize the mapped memory of the virtual machine with the cache, or an amount of data stored on the cache.

15. The system of claim 10, wherein the storage device and the destination host machine are part of the same network.

16. The system of claim 10, wherein the memory of the virtual machine on the source host machine is mapped on the storage device on system boot.

17. The system of claim 11, the processing device further to:

transmit a remaining portion of the state of the virtual machine from the source host machine to the destination host machine.

18. The system of claim 17 wherein the remaining portion of the state of the virtual machine comprises at least one of:

a CPU register, a register of a network card exposed to the virtual machine, or a device accessible to the virtual machine.

19. A non-transitory computer readable storage medium including instructions that, when executed by a processing device, cause the processing device to perform a method comprising:

receive a request to migrate a virtual machine from a source host machine to a destination host machine; and

map memory of the virtual machine on the source host machine on a storage device, wherein the storage device is accessible by the source host machine and by the destination host machine.

20. The non-transitory computer readable storage medium of claim 19, the processing device to further perform:

issuing a command to synchronize the mapped memory of the virtual machine with the cache.