System and method for raid striping

• US 6,938,123 B2
• Filed: 07/19/2002
• Issued: 08/30/2005
• Est. Priority Date: 07/19/2002
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Storage Technologies Corporation (Oracle Corporation)
• Inventors: Selkirk, Stephen S., Willis, Kenneth
• Primary Examiner(s): Verbrugge, Kevin
• Application Number:
  US10/198,863
• Publication Number:
  US 20040015655A1
• Time in Patent Office: 1,138 Days
• Field of Search: 711/114, 711/117, 710/15, 714/6, 714/114
• US Class Current: 711/114
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

In a redundant storage subsystem including an array controller and a group composed of a plurality of storage devices, a method is provided. The method includes logically parsing each storage device of the group into a corresponding number of allocation units. A stripe size is selected, and a series of writing operations is performed. Each writing operation includes selecting a subset of the plurality of storage devices based on the stripe size, and writing the stripe of data to the subset of the plurality of storage devices. The selected subset over the series of writing operations varies from operation to operation.

Claims

1. In a redundant array of inexpensive disks (RAID) subsystem including an array controller and a RAID group composed of a plurality of disk drives, the method comprising:

logically parsing each disk drive of the RAID group into a corresponding number of allocation units; and

performing a series of writing operations, each writing operation including selecting a RAID stripe size, selecting a subset of the plurality of disk drives based on the RAID stripe size, and writing the stripe of data to the subset of the plurality of disk drives, wherein the selected subset of the plurality of disk drives over the series of writing operations varies from operation to operation to achieve dynamic selection of allocation units for write operations.

2. The method of claim 1 wherein the RAID group includes disk drives that have different numbers of allocation units.

3. The method of claim 1 wherein performing the series of writing operations is performed in accordance with a log structured file system.

4. The method of claim 1 wherein each write operation includes the writing of parity data.

5. The method of claim 4 wherein performing the series of writing operations is performed in accordance with RAID 5.

6. A redundant array of inexpensive disks (RAID) system comprising:

an array controller;

a RAID group composed of a plurality of disk drives, each disk drive being logically parsed into a corresponding number of allocation units; and

a medium having instructions stored thereon to direct the array controller to perform a series of writing operations, each writing operation including selecting a subset of the plurality of disk drives based on a selected RAID stripe size, and writing the stripe of data to the subset of the plurality of disk drives, wherein the selected subset of the plurality of disk drives over the series of writing operations varies from operation to operation to achieve dynamic selection of allocation units for write operations.

7. The system of claim 6 wherein the RAID group includes disk drives that have different numbers of allocation units.

8. The system of claim 6 wherein the series of writing operations is performed in accordance with a log structured file system.

9. The system of claim 6 wherein each write operation includes the writing of parity data.

10. The system of claim 9 wherein performing the series of writing operations is performed in accordance with RAID 5.

11. In a redundant storage subsystem including an array controller and a group composed of a plurality of storage devices, the method comprising:

logically parsing each storage device of the group into a corresponding number of allocation units; and

performing a series of writing operations, each writing operation including selecting a stripe size, selecting a subset of the plurality of storage devices based on the stripe size, and writing the stripe of data to the subset of the plurality of storage devices, wherein the selected subset of the plurality of storage devices over the series of writing operations varies from operation to operation to achieve dynamic selection of allocation units for write operations.

12. The method of claim 11 wherein the group includes storage devices that have different numbers of allocation units.

13. The method of claim 11 wherein performing the series of writing operations is performed in accordance with a log structured file system.

14. The method of claim 11 wherein each write operation includes the writing of parity data.

15. The method of claim 14 wherein performing the series of writing operations is performed in accordance with RAID 5.

16. A redundant storage system comprising:

an array controller;

a group composed of a plurality of storage devices, each storage device being logically parsed into a corresponding number of allocation units; and

a medium having instructions stored thereon to direct the array controller to perform a series of writing operations, each writing operation including selecting a subset of the plurality of storage devices based on a selected stripe size, and writing the stripe of data to the subset of the plurality of storage devices, wherein the selected subset of the plurality of storage devices over the series of writing operations varies from operation to operation to achieve dynamic selection of allocation units for write operations.

17. The system of claim 16 wherein the group includes storage devices that have different numbers of allocation units.

18. The system of claim 16 wherein the series of writing operations is performed in accordance with a log structured file system.

19. The system of claim 16 wherein each write operation includes the writing of parity data.

20. The system of claim 19 wherein performing the series of writing operations is performed in accordance with RAID 5.