Method and apparatus for migrating data in a computer system

• US 7,263,590 B1
• Filed: 04/23/2003
• Issued: 08/28/2007
• Est. Priority Date: 04/23/2003
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Todd, Stephen J., Blumenau, Steven M., Cakeljic, Zoran
• Primary Examiner(s): BATAILLE, PIERRE MICHE
• Application Number:
  US10/421,478
• Time in Patent Office: 1,588 Days
• Field of Search: 711/203, 711/202, 711/170, 711/162, 711/112, 711/114, 714/6, 714/7
• US Class Current: 711/165
• CPC Class Codes: G06F 11/2082 Data synchronisation
• CPC Class Codes: G06F 12/02 Addressing or allocation; Relocation program address sequencing G06F9/00; arrangements for selecting an address in a digital store G11C8/00
• CPC Class Codes: G06F 16/214 Database migration support
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

Methods and apparatus for migrating a logical object. In one embodiment, a migration is performed by automatically determining the source location(s) of the logical object, moving the data stored therein to a target location while maintaining the availability of the data at the source location to an application program, and automatically servicing access requests from the application program at the target location after moving the data. In another embodiment, a migration is performed by automatically provisioning target location(s) to store a logical object, moving the data in the logical object to the target location(s) while maintaining its availability to an application program, and automatically servicing access requests from the application program at the target location after moving the data. In a further embodiment, a migration is performed by moving the data within a logical object from a source logical volume to a target logical volume, automatically servicing access requests from an application program at the target logical volume after moving the data, and retiring the source logical volume.

Claims

1. A method of migrating a logical object, comprising a plurality of logically associated data elements, from at least one first storage location at which the logical object is stored to at least one second storage location, the logical object storing data accessible to an application program, the method comprising computer-implemented acts of:

(A) automatically identifying the at least one first storage location at which the logical object is stored;

(B) in response to the identification of the at least one first storage location in the act (A), moving the data stored within the logical object from the at least one first storage location to the at least one second storage location;

(C) after completion of the act (B), automatically servicing access requests from the application program directed to the logical object from the at least one second storage location; and

(D) maintaining availability of the logical object to service access requests from the application program during the act (B),

wherein the method is performed in a computer system including at least one host computer and at least one storage system, wherein the at least one first storage location is provided in at least one first logical volume and the at least one second storage location is provided in at least one second logical volume, each of the logical volumes being presented by the at least one storage system to the at least one host computer and each being perceived by the at least one host computer as corresponding to a physical storage device, and wherein the act (B) includes an act of moving the data from the at least one first logical volume to the at least one second logical volume.

2. The method of claim 1, wherein the act (B) includes an act of creating at least one mirror between the at least one first logical volume and the at least one second logical volume and synchronizing the at least one mirror.

3. The method of claim 2, wherein the at least one mirror comprises a hardware mirror.

4. The method of claim 1, wherein the act (C) includes an act of automatically redirecting access requests directed to the at least one first logical volume to the at least one second logical volume.

5. The method of claim 4, further comprising an act of, during the act (B), mirroring to the at least one second logical volume all writes to the at least one first logical volume.

6. The method of claim 1, wherein the act (D) includes an act of maintaining availability of the logical object to service write requests from the application program during the act (B).

7. The method of claim 1, wherein the act (B) is initiated automatically in response to completion of the act (A) and the act (C) is initiated automatically in response to completion of the act (B).

8. The method of claim 1, further comprising an act of:

(E) retiring the at least one first logical volume upon completion of the act (C) so that the at least one first logical volume is no longer accessible.

9. The method of claim 1, wherein the at least one storage system includes first and second storage systems, wherein the at least one first logical volume is stored on the first storage system and the at least one second logical volume is stored on the second storage system.

10. The method of claim 1, wherein the at least one host computer includes at least one logical volume manager (LVM) that is assigned the at least one first logical volume and the at least one second logical volume, and wherein the act (B) is performed by the LVM.

11. The method of claim 1, wherein the acts (A), (B), (C) and (D) are performed in a manner transparent to the application program.

12. The method of claim 1, wherein the logical object includes at least a portion of a database.

13. The method of claim 1, wherein the logical object includes a file system.

14. The method of claim 1, wherein the at least one first location includes a plurality of non-contiguous storage locations.

15. The method of claim 1, wherein the at least one second location includes a plurality of non-contiguous storage locations.

16. The method of claim 1, wherein the method is performed in a computer system including at least one host computer and at least one storage system, wherein the application program executes on the at least one host computer, and wherein the method is performed by at least one utility executing on the computer system.

17. The method of claim 1, wherein the act (A) further comprises determining at least one third logical volume at which a mirror of the logical data object is stored.

18. The method of claim 17, wherein the act (B) further comprises moving the data stored within the mirror of the logical data object to at least one fourth logical volume.

19. The method of claim 18, wherein the act (B) includes an act of copying the data stored in the at least one third logical volume to the at least one fourth logical volume.

20. The method of claim 18, wherein the act (B) includes an act of creating at least one mirror between the at least one third logical volume and the at least one fourth logical volume and synchronizing the at least one mirror.

21. The method of claim 1, wherein the act (B) includes an act of copying the data stored in the logical object from the at least one first storage location to the at least one a second storage location.

22. The method of claim 1, wherein the act (D) includes an act of maintaining availability of the logical object to service access requests from the application program during acts (A), (B) and (C).

23. The method of claim 1, further comprising an act of automatically determining the at least one second storage location to accommodate the logical object.

24. The method of claim 1, wherein the acts (A), (B) and (C) are performed in response to a single instruction to migrate the logical object.

25. An apparatus for migrating a logical object from at least one first storage location at which the logical object is stored to at least one second storage location, wherein the logical object comprises a plurality of logically associated data elements and stores data accessible to an application program, the apparatus comprising at least one processor programmed to:

automatically identify the at least one first storage location at which the logical object is stored;

in response to the identification of the at least one first storage location, move the data stored within the logical object from the at least one first storage location to the at least one second storage location;

after the move of the data stored within the logical object, automatically service access requests from the application program directed to the logical object from the at least one second storage location; and

maintain the availability of the logical object to service access requests from the application program during the move of the data stored within the logical object,

wherein the migration of the logical object is performed in a computer system including at least one host computer and at least one storage system, wherein the at least one first storage location is provided in at least one first logical volume and the at least one second storage location is provided in at least one second logical volume, each of the logical volumes being presented by the at least one storage system to the at least one host computer and each being perceived by the at least one host computer as corresponding to a physical storage device, and wherein the at least one processor is programmed to move the data from the at least one first logical volume to the at least one second logical volume.

26. The apparatus of claim 25, wherein the at least one processor is programmed to create at least one mirror between the at least one first logical volume and the at least one second logical volume and synchronize the at least one mirror.

27. The apparatus of claim 26, wherein the at least one mirror comprises a hardware mirror.

28. The apparatus of claim 25, wherein the at least one processor is programmed to automatically redirect access requests directed to the at least one first logical volume to the at least one second logical volume.

29. The apparatus of claim 28, wherein the at least one processor is programmed to mirror to the at least one second logical volume all writes to the at least one first logical volume during the move of the data.

30. The apparatus of claim 29, wherein the at least one processor is programmed to maintain availability of the logical object to service write requests from the application program during the move of the data.

31. The apparatus of claim 29, wherein the at least one processor is programmed to initiate the move of the data automatically in response to completion of the automatic determination of the at least one first storage location at which the logical object is stored, and initiate the automatic servicing of access requests from the application program directed to the logical object from the at least one second storage location in response to completion of the move of the data.

32. The apparatus of claim 25, wherein the at least one processor is programmed to retire the at least one first logical volume upon completion of the automatic servicing of access requests from the application program directed to the logical object from the at least one second storage location, so that the at least one first logical volume is no longer accessible.

33. The apparatus of claim 25, wherein the at least one storage system includes first and second storage systems, wherein the at least one first logical volume is stored on the first storage system and the at least one second logical volume is stored on the second storage system.

34. The apparatus of claim 25, wherein the at least one host computer includes at least one logical volume manager (LVM) that is assigned the at least one first logical volume and the at least one second logical volume, and wherein the at least one processor is programmed to employ the LVM to perform the move of the data.

35. The apparatus of claim 25, wherein the at least one processor is programmed to perform the migration of the logical object in a manner transparent to the application program.

36. The apparatus of claim 25, wherein the logical object includes at least a portion of a database.

37. The apparatus of claim 25, wherein the logical object includes a file system.

38. The apparatus of claim 25, wherein the at least one first location includes a plurality of non-contiguous storage locations.

39. The apparatus of claim 25, wherein the at least one second location includes a plurality of non-contiguous storage locations.

40. The apparatus of claim 25, wherein the migration of the logical object is performed in a computer system which includes at least one host computer and at least one storage system, wherein the application program executes on the at least one host computer, and wherein the at least one processor is programmed to perform the migration of the logical object using at least one utility executing on the computer system.

41. The apparatus of claim 25, wherein the at least one processor is programmed to determine at least one third logical volume at which a mirror of the logical data object is stored.

42. The apparatus of claim 41, wherein the at least one processor is programmed to move the data stored within the mirror of the logical data object to at least one fourth logical volume.

43. The apparatus of claim 42, wherein the at least one processor is programmed to copy the data stored in the at least one third logical volume to the at least one fourth logical volume.

44. The apparatus of claim 42, wherein the at least one processor is programmed to create at least one mirror between the at least one third logical volume and the at least one fourth logical volume and synchronize the at least one mirror.

45. The apparatus of claim 25, wherein the at least one processor is programmed to copy the data stored in the logical object from the at least one first storage location to the at least one second storage location.

46. The apparatus of claim 25, wherein the at least one processor is programmed to maintain availability of the logical object to service access requests from the application program during the migration of the logical object.

47. The apparatus of claim 25, wherein the at least one processor is programmed to move the data stored in the logical object to the at least one second location.

48. The apparatus of claim 25, wherein the at least one processor is programmed to automatically determine the at least one second storage location to accommodate the logical object.

49. The apparatus of claim 25, wherein the at least one processor is programmed to perform the migration in response to a single instruction to migrate the logical object.

50. At least one computer-readable medium encoded with instructions that, when executed, perform a method of migrating a logical object, and from at least one first storage location at which the logical object is stored to at least one second storage location, the logical object comprising a plurality of logically associated data elements storing data accessible to an application program, the method comprising acts of:

(A) automatically identifying the at least one first storage location at which the logical object is stored;

(B) in response to the identification of the at least one first storage location in the act (A), moving the data stored within the logical object from the at least one first storage location to the at least one second storage location;

(C) after completion of the act (B), automatically servicing access requests from the application program directed to the logical object from the at least one second storage location; and

(D) maintaining availability of the logical object to service access requests from the application program during the act (B),

wherein the method is performed in a computer system including at least one host computer and at least one storage system, wherein the at least one first storage location is provided in at least one first logical volume and the at least one second storage location is provided in at least one second logical volume, each of the logical volumes being presented by the at least one storage system to the at least one host computer and each being perceived by the at least one host computer as corresponding to a physical storage device, and wherein the act (B) includes an act of moving the data from the at least one first logical volume to the at least one second logical volume.

51. The at least one computer-readable medium of claim 50, wherein the act (B) includes an act of creating at least one mirror between the at least one first logical volume and the at least one second logical volume and synchronizing the at least one mirror.

52. The at least one computer-readable medium of claim 51, wherein the at least one mirror comprises a hardware mirror.

53. The at least one computer-readable medium of claim 50, wherein the act (C) includes an act of automatically redirecting access requests directed to the at least one first logical volume to the at least one second logical volume.

54. The at least one computer-readable medium of claim 53, wherein the method further comprises an act of, during the act (B), mirroring to the at least one second logical volume all writes to the at least one first logical volume.

55. The at least one computer-readable medium of claim 50, wherein the act (D) includes an act of maintaining availability of the logical object to service write requests from the application program during the act (B).

56. The at least one computer-readable medium of claim 50, wherein the act (B) is initiated automatically in response to completion of the act (A) and the act (C) is initiated automatically in response to completion of the act (B).

57. The at least one computer-readable medium of claim 50, wherein the method further comprises an act of:

(E) retiring the at least one first logical volume upon completion of the act (C) so that the at least one first logical volume is no longer accessible.

58. The at least one computer-readable medium of claim 50, wherein the at least one storage system includes first and second storage systems, wherein the at least one first logical volume is stored on the first storage system and the at least one second logical volume is stored on the second storage system.

59. The at least one computer-readable medium of claim 50, wherein the at least one host computer includes at least one logical volume manager (LVM) that is assigned the at least one first logical volume and the at least one second logical volume, and wherein the act (B) is performed by the LVM.

60. The at least one computer-readable medium of claim 50, wherein the acts (A), (B), (C) and (D) are performed in a manner transparent to the application program.

61. The at least one computer-readable medium of claim 50, wherein the logical object includes at least a portion of a database.

62. The at least one computer-readable medium of claim 50, wherein the logical object includes a file system.

63. The at least one computer-readable medium of claim 50, wherein the at least one first location includes a plurality of non-contiguous storage locations.

64. The at least one computer-readable medium of claim 50, wherein the at least one second location includes a plurality of non-contiguous storage locations.

65. The at least one computer-readable medium of claim 50, wherein the method is performed in a computer system including at least one host computer and at least one storage system, wherein the application program executes on the at least one host computer, and wherein the method is performed by at least one utility executing on the computer system.

66. The at least one computer-readable medium of claim 50, wherein the act (A) further comprises determining at least one third logical volume at which a mirror of the logical data object is stored.

67. The at least one computer-readable medium of claim 66, wherein the act (B) further comprises moving the data stored within the mirror of the logical data object to at least one fourth logical volume.

68. The at least one computer-readable medium of claim 67, wherein the act (B) includes an act of copying the data stored in the at least one third logical volume to the at least one fourth logical volume.

69. The at least one computer-readable medium of claim 67, wherein the act (B) includes an act of creating at least one mirror between the at least one third logical volume and the at least one fourth logical volume and synchronizing the at least one mirror.

70. The at least one computer-readable medium of claim 50, wherein the act (B) includes an act of copying the data stored in the logical object from the at least one first storage location to the at least one a second storage location.

71. The at least one computer-readable medium of claim 50, wherein the act (D) includes an act of maintaining availability of the logical object to service access requests from the application program during acts (A), (B) and (C).

72. The at least one computer-readable medium of claim 50, wherein the act (B) includes an act of moving the data stored in the logical object to the at least one second location.

73. The at least one computer-readable medium of claim 50, wherein the method further comprises an act of automatically determining the at least one second storage location to accommodate the logical object.

74. The at least one computer-readable medium of claim 50, wherein the acts (A), (B) and (C) are performed in response to a single instruction to migrate the logical object.