Method and system for handling storage in response to migration of a virtual machine in a virtualization environment

1. A method for handling storage in response to migration of a virtual machine in a virtualization environment, comprising:

receiving an I/O request for an unshared virtual disk owned by a first service virtual machine, wherein a second service virtual machine receives the I/O request;

determining that the second service virtual machine which implements a storage controller is not registered as owner of the unshared virtual disk, wherein only a service virtual machine registered as owner of the unshared virtual disk is permitted to access the unshared virtual disk to implement the I/O request, and wherein the act of determining occurs in response to the second service virtual machine receiving the I/O request for the unshared virtual disk owned by the first service virtual machine;

transferring ownership of the unshared virtual disk from the first service virtual machine to the second service virtual machine; and

the second service virtual machine implementing the I/O request after obtaining ownership of the unshared virtual disk.

2. The method of claim 1 , in which the unshared virtual disk is accessed by at most one user virtual machine.

3. The method of claim 1 , in which the unshared virtual disk is implemented in a shared-nothing architecture.

4. The method of claim 1 , in which ownership of the unshared virtual disk is transferred by contacting the first service virtual machine to request that ownership be relinquished.

5. The method of claim 4 , in which a distributed configuration database module is employed to contact the first service virtual machine.

6. The method of claim 1 , in which the second service virtual machine is not registered as owner of the unshared virtual disk due to a recent migration of an associated user virtual machine from a first node to a second node.

7. The method of claim 6 , in which the second service virtual machine is on the second node.

8. A computer program product embodied on a non-transitory computer readable medium, the non-transitory computer readable medium having stored thereon a sequence of instructions which, when executed by a processor causes the processor to execute a method for handling storage in response to migration of a virtual machine in a virtualization environment, the method comprising:

receiving an I/O request for an unshared virtual disk owned by a first service virtual machine, wherein a second service virtual machine receives the I/O request;

determining that the second service virtual machine which implements a storage controller is not registered as owner of the unshared virtual disk, wherein only a service virtual machine registered as owner of the unshared virtual disk is permitted to access the unshared virtual disk to implement the I/O request, and wherein the act of determining occurs in response to the second service virtual machine receiving the I/O request for the unshared virtual disk owned by the first service virtual machine;

transferring ownership of the unshared virtual disk from the first service virtual machine to the second service virtual machine; and

implementing the I/O request by the second service virtual machine after obtaining ownership of the unshared virtual disk.

9. The computer program product of claim 8 , in which the unshared virtual disk is accessed by at most one user virtual machine.

10. The computer program product of claim 8 , in which the unshared virtual disk is implemented in a shared-nothing architecture.

11. The computer program product of claim 8 , in which ownership of the unshared virtual disk is transferred by contacting the first service virtual machine to request that ownership be relinquished.

12. The computer program product of claim 11 , in which a distributed configuration database module is employed to contact the first service virtual machine.

13. The computer program product of claim 8 , in which the second service virtual machine is not registered as owner of the unshared virtual disk due to a recent migration of an associated user virtual machine from a first node to a second node.

14. The computer program product of claim 13 , in which the second service virtual machine is on the second node.

15. A computer-based system for handling storage in response to migration of a virtual machine in a virtualization environment, comprising:

a computer processor to execute a set of program code instructions;

a memory to hold the set of program code instructions, in which the set of program code instructions comprises program code for receiving an I/O request for an unshared virtual disk owned by a first service virtual machine, wherein a second service virtual machine receives the I/O request; determining that the second service virtual machine which implements a storage controller is not registered as owner of the virtual disk, wherein only a service virtual machine registered as owner of the unshared virtual disk is permitted to access the unshared virtual disk to implement the I/O request, and wherein the act of determining occurs in response to the second service virtual machine receiving the I/O request for the unshared virtual disk owned by the first service virtual machine; transferring ownership of the unshared virtual disk from the first service virtual machine to the second service virtual machine; and implementing the I/O request by the second service virtual machine after obtaining ownership of the unshared virtual disk.

16. The system of claim 15 , in which the unshared virtual disk is accessed by at most one user virtual machine.

17. The system of claim 15 , in which the unshared virtual disk is implemented in a shared-nothing architecture.

18. The system of claim 15 , in which ownership of the unshared virtual disk is transferred by contacting the first service virtual machine to request that ownership be relinquished.

19. The system of claim 18 , in which a distributed configuration database module is employed to contact the first service virtual machine.

20. The system of claim 15 , in which the second service virtual machine is not registered as owner of the unshared virtual disk due to a recent migration of an associated user virtual machine from a first node to a second node.

21. The system of claim 20 , in which the second service virtual machine is on the second node.

22. A method for handling storage in response to migration of a virtual machine in a virtualization environment, comprising:

receiving an I/O request for an unshared virtual disk owned by a first service virtual machine, wherein a second service virtual machine that implements a storage controller receives the I/O request;

determining that the storage controller is not currently registered as owner of the unshared virtual disk, wherein only a service virtual machine registered as owner of the unshared virtual disk is permitted to access the unshared virtual disk to implement the I/O request, and wherein the act of determining occurs in response to the second service virtual machine receiving the I/O request for the unshared virtual disk owned by the first service virtual machine;

transferring ownership of the unshared virtual disk from the first service virtual machine to the second service virtual machine; and

the storage controller implementing the I/O request after obtaining ownership of the unshared virtual disk.

23. The method of claim 22 , in which the unshared virtual disk is accessed by at most one user virtual machine.

24. The method of claim 22 , in which the unshared virtual disk is implemented in a shared-nothing architecture.

25. The method of claim 22 , in which ownership of the unshared virtual disk is obtained by contacting the first service virtual machine to request that ownership be relinquished.

26. The method of claim 25 , in which a distributed configuration database module is employed to contact the first service virtual machine.

27. The method of claim 22 , in which the second service virtual machine is not registered as owner of the unshared virtual disk due to a recent migration of an associated user virtual machine from a first node to a second node.

28. The method of claim 27 , in which the second service virtual machine is on the second node.

29. A computer program product embodied on a non-transitory computer readable medium, the non-transitory computer readable medium having stored thereon a sequence of instructions which, when executed by a processor causes the processor to execute a method for handling storage in response to migration of a virtual machine in a virtualization environment, the method comprising:

receiving an I/O request for an unshared virtual disk owned by a first service virtual machine, wherein a second service virtual machine that implements a storage controller receives the I/O request;

determining that the storage controller is not currently registered as owner of the unshared virtual disk, wherein only a service virtual machine registered as owner of the unshared virtual disk is permitted to access the unshared virtual disk to implement the I/O request, and wherein the act of determining occurs in response to the second service virtual machine receiving the I/O request for the unshared virtual disk owned by the first service virtual machine;

transferring ownership of the unshared virtual disk from the first service virtual machine to the second service virtual machine; and

the storage controller implementing the I/O request after obtaining ownership of the unshared virtual disk.

30. The computer program product of claim 29 , in which the unshared virtual disk is accessed by at most one user virtual machine.

31. The computer program product of claim 29 , in which the unshared virtual disk is implemented in a shared-nothing architecture.

32. The computer program product of claim 29 , in which ownership of the unshared virtual disk is obtained by contacting the first service virtual machine to request that ownership be relinquished.

33. The computer program product of claim 32 , in which a distributed configuration database module is employed to contact the first service virtual machine.

34. The computer program product of claim 29 , in which the second service virtual machine is not registered as owner of the unshared virtual disk due to a recent migration of an associated user virtual machine from a first node to a second node.

35. The computer program product of claim 34 , in which the second service virtual machine is on the second node.

36. A computer-based system for handling storage in response to migration of a virtual machine in a virtualization environment, comprising:

a computer processor to execute a set of program code instructions;

a memory to hold the set of program code instructions, in which the set of program code instructions comprises program code for receiving an I/O request for an unshared virtual disk owned by a first service virtual machine, wherein a second service virtual machine that implements a storage controller receives the I/O request; determining that the storage controller is not currently registered as owner of the unshared virtual disk, wherein only a service virtual machine registered as owner of the unshared virtual disk is permitted to access the unshared virtual disk to implement the I/O request, and wherein the act of determining occurs in response to the second service virtual machine receiving the I/O request for the unshared virtual disk owned by the first service virtual machine; transferring ownership of the unshared virtual disk from the first service virtual machine to the second service virtual machine; and having the storage controller implementing the I/O request after obtaining ownership of the unshared virtual disk.

37. The system of claim 36 , in which the unshared virtual disk is accessed by at most one user virtual machine.

38. The system of claim 36 , in which the unshared virtual disk is implemented in a shared-nothing architecture.

39. The system of claim 36 , in which ownership of the unshared virtual disk is obtained by contacting the first service virtual machine to request that ownership be relinquished.

40. The system of claim 39 , in which a distributed configuration database module is employed to contact the first service virtual machine.

41. The system of claim 36 , in which the second service virtual machine is not registered as owner of the unshared virtual disk due to a recent migration of an associated user virtual machine from a first node to a second node.

42. The system of claim 41 , in which the second service virtual machine is on the second node.