Method for writing contiguous arrays of stripes in a RAID storage system using mapped block writes

• US 7,200,715 B2
• Filed: 03/21/2002
• Issued: 04/03/2007
• Est. Priority Date: 03/21/2002
• Status: Expired due to Term

• Current Assignee: NetApp, Inc.
• Original Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Inventors: Kleiman, Steven R., Sundaram, Rajesh, Doucette, Douglas P., Viswanathan, Srinivasan, Strange, Stephen H.
• Primary Examiner(s): NGUYEN, THAN VINH
• Application Number:
  US10/105,034
• Publication Number:
  US 20030182502A1
• Time in Patent Office: 1,839 Days
• Field of Search: 711/112, 711/114, 711/118, 711/154, 711/155, 711/158
• US Class Current: 711/114
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/0655 Vertical data movement, i.e. input-output transfer; data movement between one or more hosts and one or more storage devices
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

The invention features a method for controlling storage of data in a plurality of storage devices each including storage blocks, for example, in a RAID array. The method includes receiving a plurality of write requests associated with data, and buffering the write requests. A file system defines a group of storage blocks, responsive to disk topology information. The group includes a plurality of storage blocks in each of the plurality of storage devices. Each data block of the data to be written is associated with a respective one of the storage blocks, for transmitting the association to the plurality of storage devices.

Claims

1. A method for controlling storage of data blocks in a plurality of storage devices, the method comprising:

buffering a plurality of write requests associated with the data blocks for a single write transaction;

defining a group of storage blocks, the group comprising a plurality of storage blocks in each of the plurality of storage devices; and

associating each data block with a respective one of the storage blocks across the plurality of stripes to generate an association; and

transmitting the association to a storage device manager for processing of the single write transaction.

2. The method of claim 1, further comprising receiving by a file system the plurality of write requests, and transmitting from the file system to the storage device manager the association for processing of the single write transaction, wherein the storage device manager comprises a RAID layer.

3. The method of claim 1, wherein associating comprises associating each data block of at least one of the write requests with storage blocks of only one of the plurality of storage devices.

4. The method of claim 1, wherein defining the group of storage blocks comprises receiving by the file system from the storage device manager configuration information of the plurality of storage devices.

5. The method of claim 4, wherein the configuration information comprises disk topology information.

6. The method of claim 1, wherein the group of storage blocks comprises more than one stripe in a RAID group.

7. The method of claim 6, wherein the group of storage blocks comprises more than one contiguous stripe.

8. The method of claim 7, further comprising transmitting the association and the data to the plurality of storage devices to store each data block at the respective one of the storage blocks of the more than one contiguous stripe.

9. The method of claim 6, wherein the plurality of storage devices comprises more than one RAID group, and defining the group of storage blocks comprises defining the group of storage blocks from storage blocks in a first RAID group.

10. The method of claim 9, further comprising defining a second group of storage blocks in a second RAID group for association with data associated with a second plurality of write requests for processing of a second write transaction.

11. The method of claim 1, further comprising queuing a plurality of associations by the storage device manager for processing of a plurality of write transactions.

12. The method of claim 11, further comprising processing the plurality of write transactions by the storage manager in an order derived from a plurality of priorities associated with the plurality of write transactions.

13. The method of claim 1, wherein the group of storage blocks comprises a same quantity of storage blocks in each one of the plurality of storage devices.

14. The method of claim 13, wherein each of the plurality of storage blocks comprises contiguous storage blocks.

15. The method of claim 1, wherein the group of storage blocks comprises allocated and unallocated storage blocks.

16. The method of claim 15, wherein defining the group further comprises selecting an unallocated storage block having a lowest block identifier of any unallocated storage block as a storage block having a lowest storage block identifier of any storage block in the group.

17. The method of claim 1, wherein the write requests comprise data to be written.

18. A device for controlling storage of data in a plurality of storage devices each having storage blocks configured in a plurality of parallel stripes, the device comprising:

a buffer collecting write requests, each request associated with data blocks;

a processor defining a group of storage blocks, the group having a plurality of storage blocks in each of the plurality of storage devices, the processor associating each data block with a respective one of the storage blocks across the plurality of stripes for a single write transaction; and

a transmitter transmitting an association to a storage device manager for processing of the single write transaction.

19. A device for controlling storage of data in a plurality of storage devices each having storage blocks configured in a plurality of parallel stripes, the device comprising:

means for buffering a plurality of write requests associated with data blocks for a single write transaction;

means for defining a group of storage blocks, the group having a plurality of storage blocks in each of the plurality of storage devices; and

means for associating each data block with a respective one of the storage blocks across the plurality of stripes, for transmitting an association to a storage device manager for processing of the single write transaction.

20. A computer readable media, comprising:

the computer readable media containing instructions for execution in a processor for the practice of the method of,

buffering a plurality of write requests associated with data blocks for a single write transaction;

defining a group of storage blocks, the group comprising a plurality of storage blocks configured in a plurality of parallel stripes in each of a plurality of storage devices; and

associating each data block with a respective one of the storage blocks across the plurality of stripes, for transmitting an association to a storage device manager for processing of the single write transaction.

21. A method for controlling storage of data, comprising:

receiving one or more write requests associated with data blocks;

receiving topological information associated with storage blocks configured in a plurality of parallel stripes of a storage system;

associating the data blocks with one or more storage blocks across the plurality of stripes as an association; and

writing the data blocks, in response to the association, to the one or more storage devices in a single write request.

22. The method of claim 21, further comprising:

transmitting the association to a storage device manager.

23. The method of claim 21, further comprising:

associating each data block with a single storage block.

24. The method of claim 21, further comprising:

storing the data blocks in the association.

25. The method of claim 21, further comprising:

storing the data blocks in a memory of the storage system.

26. The method of claim 21, further comprising:

creating an array as the association.

27. The method of claim 21, further comprising:

buffering a plurality of write requests into the single write request.

28. The method of claim 27, further comprising:

buffering, in a buffer, the plurality of write requests into the single write request until a predetermined criteria is met.

29. The method of claim 28, further comprising:

meeting the criteria when a buffer is full.

30. The method of claim 28, further comprising:

meeting the criteria when the single write request is a predetermined logical length.

31. The method of claim 30, further comprising:

receiving topological information of a plurality of storage devices of the storage system.

32. The method of claim 31, further comprising:

using a RAID system as the plurality of storage devices.

33. The method of claim 21, further comprising:

using a plurality of disks for the storage system.

34. The method of claim 21, further comprising:

transmitting the association to the storage device manager.

35. The method of claim 21, further comprising:

organizing the association as a combination of columns and rows.

36. The method of claim 35, further comprising:

associating each column with a storage device.

37. The method of claim 36, further comprising:

associating each row with a stripe of the storage device.

38. The method of claim 37, further comprising:

arranging the association as a plurality of stripes on a plurality of storage devices.

39. A storage system, comprising:

a file system, the file system to receive one of more write requests associated with data blocks;

a storage device manager, the storage device manager to generate topological information of storage blocks configured in a plurality of parallel stripes of one or more storage devices, and to send the topological information to the file system; and

an association generated in the file system, the association to associate the data blocks with one or more storage blocks across the plurality of stripes of the one or more storage devices, the association to be sent to the storage device manager, the storage device manager to write the data blocks, in response to the association, to the one or more storage blocks as a single write request.

40. The storage system of claim 39, further comprising:

an association that associates each data block with a single storage block.

41. The storage system of claim 39, further comprising:

a memory to buffer the data blocks for the write request to the one or more storage devices.

42. The storage system of claim 39, further comprising:

a memory to store the association containing the data blocks.

43. The storage system of claim 39, further comprising:

one or more storage devices having storage blocks.

44. The storage system of claim 39, further comprising:

an array as the association.

45. The storage system of claim 39, further comprising:

a buffer in the file system to receive the one or more write requests.

46. The storage system of claim 39, further comprising:

an arrangement of columns and rows in the association.

47. The storage system of claim 46, further comprising:

each column representing a storage device of the one or more storage devices.

48. The storage system of claim 46, further comprising:

each row representing a stripe of the one or more storage devices.

49. The storage system of claim 39, further comprising:

a plurality of disks as the one or more storage devices.

50. The storage system of claim 39, further comprising:

a RAID system as the plurality of storage devices.

51. A storage system, comprising:

means for receiving one or more write requests associated with data blocks;

means for receiving topological information associated with storage blocks configured in a plurality of parallel stripes of a storage system;

means for associating the data blocks with one or more storage blocks across the plurality of stripes as an association; and

means for writing the data blocks, in response to the association, to the one or more storage devices in a single write request.

52. A computer readable media, comprising:

the computer readable media containing instructions for execution in a processor for the practice of the method of,

receiving one or more write requests associated with data blocks;

receiving topological information associated with storage blocks configured in a plurality of parallel stripes of a storage system;

associating the data blocks with one or more storage blocks across the plurality of stripes as an association; and

writing the data blocks, in response to the association, to the one or more storage devices in a single write request.