Virtual machine migration

• US 20080270564A1
• Filed: 04/25/2007
• Published: 10/30/2008
• Est. Priority Date: 04/25/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Fries, Robert, Rangegowda, Dharshan
• Granted Patent: US 8,479,194 B2
• Time in Patent Office: Days
• US Class Current: 709/212
• CPC Class Codes: G06F 2009/4557 Distribution of virtual machine instances; Migration and load balancing
• CPC Class Codes: G06F 9/455 Emulation; Interpretation; Software simulation, e.g. virtualisation or emulation of application or operating system execution engines
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects
• CPC Class Codes: G06F 9/5088 involving task migration

Abstract

Virtual machine migration is described. In embodiment(s), a virtual machine can be migrated from one host computer to another utilizing LUN (logic unit number) masking. A virtual drive of the virtual machine can be mapped to a LUN mask associates the LUN with a host computer. The LUN mask can be changed to unmask the LUN to a second computer to migrate the virtual machine from the host computer to the second computer.

Claims

1. A method, comprising:

identifying one or more virtual drives of a virtual machine that are each mapped to a respective LUN (logical unit number) of a storage array;

mapping the one or more virtual drives to a mapping file that is stored on a LUN of the storage array;

unmasking each LUN to migrate the virtual machine from the first host computer to the second host computer; and

creating the virtual machine on the second host computer according to the mapping file such that the one or more virtual drives are each mapped from the respective LUN of the storage array to the virtual machine on the second host computer.

2. A method as recited in claim 1, further comprising:

deleting the virtual machine from the first host computer; and

disassociating the one or more virtual drives from the first host computer.

3. A method as recited in claim 1, wherein identifying the one or more virtual drives, mapping the one or more virtual drives, unmasking each LUN, and creating the virtual machine are each restartable tasks of virtual machine migration such that if a task fails to be completed, the virtual machine migration can be restarted from the task that failed.

4. A method as recited in claim 1, further comprising determining that each LUN is accessible to the second host computer through a storage interface of the storage array.

5. A method as recited in claim 4, further comprising:

identifying one or more communication ports of the storage interface that each LUN is mapped to for data communication;

determining whether the first host computer can access the storage array via any of the one or more identified communication ports;

determining whether the second host computer can access the storage array via any of the one or more identified communication ports; and

migrating the virtual machine from the first host computer to the second host computer in an event that the first host computer can access the storage array via at least one of the identified communication ports, and in an event that the second host computer can access the storage array via at least one of the identified communication ports.

6. A method as recited in claim 1, wherein unmasking each LUN to the second host computer includes logging each LUN into an iSCSI (Internet Small Computer System Interface) network that communicatively links a storage interface of the storage array to the first host computer and to the second host computer.

7. A method as recited in claim 1, further comprising creating a LUN of the storage array in accordance with configuration reliability information that defines a reliability level of the LUN.

8. A virtualization system, comprising:

a virtual machine configured to execute on a first host computer;

a LUN (logical unit number) of a storage array that is mapped to a virtual drive of the virtual machine; and

a LUN mask configured to associate the LUN with the first host computer of the virtual machine, the LUN mask being configurable to unmask the LUN to migrate the virtual machine from the first host computer to the second host computer.

9. A computer system as recited in claim 8, wherein the LUN of the storage array is configured to reference a mapping file that maps the virtual drive of the virtual machine to the LUN.

10. A computer system as recited in claim 8, further comprising a virtual manager configured to initiate and manage migration of the virtual machine from the first host computer to the second host computer.

11. A computer system as recited in claim 10, wherein the virtual manager is further configured to initiate deletion of the virtual machine from the first host computer, and initiate disassociation of the virtual drive from the first host computer.

12. A computer system as recited in claim 10, wherein the virtual manager is further configured to determine that the LUN is accessible to the second host computer through a storage interface of the storage array to facilitate the migration of the virtual machine from the first host computer to the second host computer.

13. A computer system as recited in claim 12, wherein the virtual manager is further configured to:

identify one or more communication ports of the storage interface that the LUN is mapped to for data communication;

determine whether the first host computer can access the storage array via any of the one or more identified communication ports;

determine whether the second host computer can access the storage array via any of the one or more identified communication ports; and

said initiate and manage the migration of the virtual machine from the first host computer to the second host computer in an event that the first host computer can access the storage array via at least one of the identified communication ports, and in an event that the second host computer can access the storage array via at least one of the identified communication ports.

14. A computer system as recited in claim 8, further comprising an iSCSI (Internet Small Computer System Interface) network configured to communicatively link a storage interface of the storage array to the first host computer and to the second host computer, and wherein the LUN is unmasked to the second host computer when the LUN is logged out of the first host computer and logged into the second host computer.

15. One or more computer-readable storage media comprising computer-executable instructions that, when executed, direct a virtual manager to:

initiate creation of a LUN (logical unit number) on a storage array;

unmask the LUN to the virtual manager to associate the LUN with the virtual manager;

initiate creation of a virtual machine from a virtual machine template, the virtual machine having an associated virtual drive and configured to execute on a host computer; and

unmask the LUN to map the LUN from the virtual manager to the virtual drive of the virtual machine on the host computer.

16. One or more computer-readable storage media as recited in claim 15, further comprising computer-executable instructions that, when executed, direct the virtual manager to receive one or more configuration inputs to define a reliability configuration level of the storage array when the virtual machine is created.

17. One or more computer-readable storage media as recited in claim 15, further comprising computer-executable instructions that, when executed, direct the virtual manager to:

map the virtual drive to a mapping file that is stored on the LUN of the storage array;

unmask the LUN from the host computer to an additional host computer to migrate the virtual machine from the host computer to the additional host computer; and

initiate creation the virtual machine on the additional host computer according to the mapping file such that the virtual drive is mapped from the LUN of the storage array to the virtual machine on the additional host computer.

18. One or more computer-readable storage media as recited in claim 17, further comprising computer-executable instructions that, when executed, direct the virtual manager to:

determine that the LUN is accessible to the additional host computer through a storage interface of the storage array;

identify one or more communication ports of the storage interface that the LUN is mapped to for data communication;

determine whether the host computer can access the storage array via any of the one or more identified communication ports;

determine whether the additional host computer can access the storage array via any of the one or more identified communication ports; and

initiate migration of the virtual machine from the host computer to the additional host computer in an event that the host computer can access the storage array via at least one of the identified communication ports, and in an event that the additional host computer can access the storage array via at least one of the identified communication ports.

19. One or more computer-readable storage media as recited in claim 15, further comprising computer-executable instructions that, when executed, direct the virtual manager to unmask an additional LUN on the storage array to migrate the additional LUN from an additional host computer to an additional virtual drive of the virtual machine on the host computer, the virtual drive and the additional virtual drive each being mapped to respective databases of the virtual machine.

20. One or more computer-readable storage media as recited in claim 15, further comprising computer-executable instructions that, when executed, direct the virtual manager to:

initiate creation of a virtual machine instantiation of the virtual machine on an additional host computer, the virtual machine instantiation having an additional virtual drive and configured to execute on the additional host computer; and

unmask the LUN to map the LUN from the host computer to the additional virtual drive of the virtual machine instantiation on the additional host computer.