Clearing metadata tracks in a storage system

• US 20060106829A1
• Filed: 11/18/2004
• Published: 05/18/2006
• Est. Priority Date: 11/18/2004
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Spear, Gail A., Stanley, Warren K., Springer, James A., Budaya, Angelique R., Mahar, Aaron S.
• Granted Patent: US 8,676,748 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/10 File systems; File servers

Abstract

Methods, systems, computer program products and methods for deploying computing infrastructure for clearing metadata in a storage subsystem. The method includes identifying one or more metadata tracks to clear, receiving a request from a client to clear the identified tracks, quiescing any active processes, clearing the identified tracks and resuming the quiesced processes. The request may be a single request operable to clear all metadata tracks. Alternatively, target volumes having metadata tracks to be cleared are identified and a request is received from a client for each target volume. A dynamic function list may also be created for each target volume, the list including list of functions in which the target volume is associated. After active processes are quiesced, each function in the dynamic function list of each target volume is invoked whereby the metadata tracks are cleared. The quiesced processes are then resumed.

Claims

1. A method for clearing metadata in a storage subsystem, comprising:

identifying one or more metadata tracks to clear;

receiving a clear metadata tracks (CMT) request from a client to clear the identified metadata tracks;

quiescing any active processes;

clearing the identified metadata tracks; and

resuming the quiesced processes.

2. The method of claim 1, further comprising identifying one or more types of metadata to be cleared and receiving the CMT request comprises receiving a CMT request for each identified type of metadata, each CMT request including an identification of a metadata type and an identification of one or more metadata tracks associated with the metadata type.

3. The method of claim 2, wherein each CMT request is directed at all of the metadata tracks of an identified type stored in one of the group of levels consisting of a storage controller, a logical subsystem and a volume.

4. The method of claim 3, wherein clearing the identified metadata tracks for each level is performed substantially in parallel.

5. The method of claim 2, further comprising creating one or more in-memory structures, each containing an identified metadata type and the one or more metadata tracks associated with the metadata type.

6. The method of claim 2, further comprising creating one or more in-memory structures, each containing an identified metadata track and an identified metadata type with which the metadata track is associated.

7. The method of claim 2, further comprising:

transmitting an acknowledgement of receipt of the CMT requests; and

receiving a quiesce command to initiate performance of the quiescing of active processes.

8. The method of claim 1, wherein the request comprises a single CMT command operable to clear all metadata tracks on the storage subsystem without affecting storage subsystem configuration data.

9. The method of claim 8, further comprising;

creating an in-memory structure containing an identifying one or more metadata tracks associated with a metadata type; and

upon receipt of the CMT request, setting an indication in the structure that all metadata tracks are to be cleared.

10. The method of claim 1, wherein one or more volumes is a target of the CMT request, the method further comprising:

after receiving the CMT request, generating a dynamic function list for each target volume, the dynamic function list including a list of functions in which the target volume is associated; and

in response to the CMT request, invoking each function in the dynamic function list.

11. The method of claim 10, wherein the functions in the function list comprise copy services functions.

12. A method for clearing global metadata (metadata) in a storage subsystem, comprising:

receiving a single clear metadata tracks (CMT) request from a client to clear all global metadata (metadata) tracks associated with the storage subsystem;

quiescing any active processes;

clearing the metadata tracks without affecting storage subsystem configuration data; and

resuming the quiesced processes.

13. The method of claim 12, further comprising:

transmitting an acknowledgement of receipt of the CMT request; and

receiving a quiesce command to initiate performance of the quiescing of active processes.

14. The method of claim 12, further comprising:

setting all CMT bits in an in-memory control structure;

detecting the set bits; and

generating one or more task control blocks to execute the clearing of the metadata tracks.

15. The method of claim 12, wherein clearing the metadata tracks is performed substantially in parallel.

16. A method for clearing metadata a storage subsystem, comprising:

identifying one or more target volumes having one or more metadata tracks to clear;

receiving a clear metadata tracks (CMT) request from a client for each target volume;

generating a dynamic function list for each target volume, the dynamic function list including a list of functions in which the target volume is associated;

quiescing any active processes;

for each target volume, invoking each function in the dynamic function list whereby the metadata tracks are cleared; and

resuming the quiesced processes.

17. The method of claim 16, wherein invoking each function in the dynamic function list comprises:

generating a task control block (TCB) for each target volume, the TCB including the list of functions with which the tarrget volume is associated; and

executing the TCB for each target volume.

18. The method of claim 16, wherein the functions in the function list comprise copy services functions.

19. The method of claim 16, further comprising:

transmitting an acknowledgement of receipt of the CMT requests; and

receiving a quiesce command to initiate performance of the quiescing of active processes.

20. A storage subsystem for clearing metadata, comprising:

a cache storage;

a nonvolatile journaling storage;

means for receiving a request to clear identified metadata; and

metadata management code, comprising;

means for directing that any active processes be quiesced;

means for directing that the identified metadata tracks be cleared; and

means for directing that the quiesced processes be resumed.

21. The storage subsystem of claim 20, wherein the means for receiving the request comprises measn for receiving a clear metadata tracks (CMT) request for each of a plurality to identified types of metadata, each CMT request including an identification of a metadata type and an identification of one or more metadata tracks associated with the metadata type.

22. The storage subsystem of claim 21, wherein each CMT request is directed at all of the metadata tracks of an identified type stored in one of the group of levels consisting of a storage controller, a logical subsystem and a volume.

23. The storage subsystem of claim 22, wherein the means for clearing the identified metadata tracks for each level comprises means for clearing the identified metadata tracks substantially in parallel.

24. The storage subsystem of claim 21, further comprising one or more in-memory structures, each comprising an identified metadata type and the one or more metadata tracks associated with the metadata type.

25. The storage subsystem of claim 21, further comprising one or more in-memory structures, each comprising an identified metadata track and an identified metadata type with which the metadata track is associated.

26. The storage subsystem of claim 20, wherein the request comprises a single clear metadata tracks (CMT) command operable to clear all metadata tracks on the storage subsystem without affecting storage subsystem configuration data.

27. The storage subsystem of claim 26, further comprising:

an in-memory structure containing an identifying one or more metadata tracks associated with a metadata type; and

the metadata management code further comprises means for setting an indication in the structure that all metadata tracks are to be cleared upon receipt of the CMT request.

28. The storage subsystem of claim 20, wherein one or more volumes is a target of the clear metadata tracks (CMT) request, the metadata management code further comprising:

means for generating a dynamic function list for each target volume after receiving the CMT request, the dynamic function list including a list of functions in which the target volume is associated; and

means for invoking each function in the dynamic function list in response to the CMT request.

29. The storage subsystem of claim 28, wherein the functions in the function list comprise copy services functions.

30. A storage subsystem, comprising:

means for receiving a single clear metadata tracks (CMT) request from a client to clear all metadata tracks associated with the storage subsystem;

means for quiescing any active processes;

means for clearing the metadata tracks without affecting storage subsystem configuration data; and

means for resuming the quiesced processes.

31. The storage subsystem of claim 30, further comprising:

means for transmitting an acknowledgement of receipt of the CMT request; and

means for receiving a quiesce command to initiate performance of the quiescing of active processes.

32. The storage subsystem of claim 30, further comprising:

means for setting all CMT bits in an in-memory control structure;

means for detecting the set bits; and

means for generating one or more task control blocks to execute the clearing of the metadata tracks.

33. The storage subsystem of claim 30, wherein the means for clearing the metadata tracks comprises clearing the metadata tracks substantially in parallel.

34. A storage subsystem for clearing metadata, comprising:

means for identifying one or more target volumes having one or more metadata tracks to clear;

means for receiving a clear metadata tracks (CMT) request from a client for each target volume;

means for generating a dynamic function list for each target volume, the dynamic function list including a list of functions in which the target volume is associated;

means for quiescing any active processes;

means for for each target volume, invoking each function in the dynamic function list whereby the metadata tracks are cleared; and

means for resuming the quiesced processes.

35. The storage subsystem of claim 34, wherein the means for invoking each function in the dynamic function list comprises:

means for generating a task control block (TCB) for each target volume, the TCB including the list of functions with which the tarrget volume is associated; and

means for executing the TCB for each target volume.

36. The storage subsystem of claim 34, wherein the functions in the function list comprise copy services functions.

37. The storage subsystem of claim 34, further comprising:

means for transmitting an acknowledgement of receipt of the CMT requests; and

means for receiving a quiesce command to initiate performance of the quiescing of active processes.

38. A computer program product of a computer readable medium usable with a programmable computer, the computer program product having computer-readable code embodied therein for for clearing metadata in a storage subsystem, the computer-readable code comprising instructions for:

identifying one or more metadata tracks to clear;

receiving a clear metadata tracks (CMT) request from a client to clear the identified metadata tracks;

quiescing any active processes;

clearing the identified metadata tracks; and

resuming the quiesced processes.

39. The computer program product of claim 38, further comprising instructions for identifying one or more types of metadata to be cleared and receiving the CMT request comprises receiving a CMT request for each identified type of metadata, each CMT request including an identification of a metadata type and an identification of one or more metadata tracks associated with the metadata type.

40. The computer program product of claim 39, wherein each CMT request is directed at all of the metadata tracks of an identified type stored in one of the group of levels consisting of a storage controller, a logical subsystem and a volume.

41. The computer program product of claim 40, wherein the instructions for clearing the identified metadata tracks for each level comprise instructions for clearing the identified metadata tracks substantially in parallel.

42. The computer program product of claim 39, further comprising instructions for creating one or more in-memory structures, each containing an identified metadata type and the one or more metadata tracks associated with the metadata type.

43. The computer program product of claim 39, further comprising instructions for creating one or more in-memory structures, each containing an identified metadata track and an identified metadata type with which the metadata track is associated.

44. The computer program product of claim 39, further comprising instructions for:

transmitting an acknowledgement of receipt of the CMT requests; and

receiving a quiesce command to initiate performance of the quiescing of active processes.

45. The computer program product of claim 38, wherein the request comprises a single CMT command operable to clear all metadata tracks on the storage subsystem without affecting storage subsystem configuration data.

46. The computer program product of claim 45, further comprising instructions for:

creating an in-memory structure containing an identifying one or more metadata tracks associated with a metadata type; and

upon receipt of the CMT request, setting an indication in the structure that all metadata tracks are to be cleared.

47. The computer program product of claim 38, wherein one or more volumes is a target of the CMT request, the method further comprising:

after receiving the CMT request, generating a dynamic function list for each target volume, the dynamic function list including a list of functions in which the target volume is associated; and

in response to the CMT request, invoking each function in the dynamic function list.

48. The computer program product of claim 47, wherein the functions in the function list comprise copy services functions.

49. A method for deploying computing infrastructure, comprising integrating computer readable code into a computing system, wherein the code, in combination with the computing system, is capable of performing the following:

identifying one or more metadata tracks to clear;

receiving a clear metadata tracks (CMT) request from a client to clear the identified metadata tracks;

quiescing any active processes;

clearing the identified metadata tracks; and

resuming the quiesced processes.

50. The method of claim 49, wherein the code, in combination with the computing system, is further capable of identifying one or more types of metadata to be cleared and receiving the CMT request comprises receiving a CMT request for each identified type of metadata, each CMT request including an identification of a metadata type and an identification of one or more metadata tracks associated with the metadata type.

51. The method of claim 50, wherein each CMT request is directed at all of the metadata tracks of an identified type stored in one of the group of levels consisting of a storage controller, a logical subsystem and a volume.

52. The method of claim 51, wherein clearing the identified metadata tracks for each level is performed substantially in parallel.

53. The method of claim 50, wherein the code, in combination with the computing system, is further capable of creating one or more in-memory structures, each containing an identified metadata type and the one or more metadata tracks associated with the metadata type.

54. The method of claim 50, wherein the code, in combination with the computing system, is further capable of creating one or more in-memory structures, each containing an identified metadata track and an identified metadata type with which the metadata track is associated.

55. The method of claim 50, wherein the code, in combination with the computing system, is further capable of performing the following:

transmitting an acknowledgement of receipt of the CMT requests; and

receiving a quiesce command to initiate performance of the quiescing of active processes.

56. The method of claim 49, wherein the request comprises a single CMT command operable to clear all metadata tracks on the storage subsystem without affecting storage subsystem configuration data.

57. The method of claim 56, wherein the code, in combination with the computing system, is further capable of performing the following:

creating an in-memory structure containing an identifying one or more metadata tracks associated with a metadata type; and

upon receipt of the CMT request, setting an indication in the structure that all metadata tracks are to be cleared.

58. The method of claim 49, wherein one or more volumes is a target of the CMT request, the method further comprising:

after receiving the CMT request, generating a dynamic function list for each target volume, the dynamic function list including a list of functions in which the target volume is associated; and

in response to the CMT request, invoking each function in the dynamic function list.

59. The method of claim 58, wherein the functions in the function list comprise copy services functions.