Method and computer program product to increase I/O write performance in a redundant array

• US 20060136654A1
• Filed: 12/16/2004
• Published: 06/22/2006
• Est. Priority Date: 12/16/2004
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Franklin, Chris Robert
• Granted Patent: US 7,730,257 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0683 Plurality of storage devices

Abstract

A method and related computer program product for achieving high performance I/O write rates in a redundant array using a fully recoverable communication queue stored in NVRAM on a RAID controller comprising, receiving an I/O write request from an application, determining if the I/O request is an inline write command, writing inline write commands into a command queue stored in NVRAM, notifying the application generating the I/O request of command completion and requesting the operating system for further I/Os.

Claims

1. A method of achieving high performance I/O write rates in a redundant array of independent disks (RAID) using a fully recoverable command queue stored in non-volatile random access memory (NVRAM) on a RAID controller, comprising:

(a) receiving an I/O write request from an application;

(b) writing an inline write command into said command queue stored in said NVRAM; and

(c) notifying said application of I/O write completion.

2. The method of claim 1, further comprising:

determining write data size for said I/O write request prior to step (b).

3. The method of claim 2, further comprising:

issuing said write command to a corresponding direct memory access (DMA) controller in said array if said write data size exceeds the optimum inline maximum.

4. The method of claim 3, further comprising:

notifying said application generating said I/O write request of command completion after said DMA controller has completed said I/O write request and written a response indicating command completion to a response queue.

5. The method of claim 1, further comprising:

reading an I/O write request from said command queue subsequent to step (c).

6. The method of claim 5, further comprising:

determining if said write request is to be executed using inline data.

7. The method of claim 6, further comprising:

processing said write request as an inline write command if said write request is to be executed using inline data.

8. The method of claim 7, further comprising:

removing said write request from said command queue after completion of said write request.

9. The method of claim 6, further comprising:

removing said write request from said command queue if said write request is to be processed using a DMA controller.

10. The method of claim 9, further comprising:

signaling the corresponding DMA controller in said array to transfer write data to said NVRAM.

11. The method of claim 10, further comprising:

writing a response to a response queue indicating command completion after said write data has been transferred to said NVRAM.

12. The method of claim 1, further comprising:

booting the CPU on said RAID controller upon recovery from shutdown.

13. The method of claim 12, further comprising:

checking said command queue stored in said NVRAM for inline write commands.

14. The method of claim 13, further comprising:

issuing said inline write commands to respective disks in said array upon detecting the presence of said inline write commands in said command queue.

15. The method of claim 14, further comprising:

completing initialization of said RAID controller subsequent to issuing all inline write commands in said command queue.

16. The method of claim 13, further comprising:

completing initialization of said RAID controller upon detecting an absence of said inline write commands in said command queue.

17. A computer program product comprising a computer useable medium including control logic stored therein for achieving high performance I/O write rates in a redundant array using a fully recoverable command queue stored in NVRAM on a RAID controller, comprising:

first control logic means for enabling the computer to receive an I/O write request from an application;

second control logic means for enabling the computer to write an inline write command into said command queue stored in said NVRAM; and

third control logic means for enabling the computer to notify said application of I/O write completion.

18. The computer program product of claim 17, further comprising:

fourth control logic means for enabling the computer to determine write data size for said I/O write request.

19. The computer program product of claim 18, further comprising:

fifth control logic means for enabling the computer to issue said write command to a corresponding DMA controller in said array if said write data size exceeds the optimum inline maximum.

20. The computer program product of claim 19, further comprising:

sixth control logic means for enabling the computer to notify said application generating said I/O write request of command completion after said DMA controller has completed said I/O write request and written a response to a response queue.

21. The computer program product of claim 17, further comprising:

fourth control logic means for enabling the computer to read an I/O write request from said command queue.

22. The computer program product of claim 21, further comprising:

fifth control logic means for enabling the computer to determine if said write request is to be executed using inline data.

23. The computer program product of claim 22, further comprising:

sixth control logic means for enabling the computer to process said write request as an inline write command if said write request is to be executed using inline data.

24. The computer program product of claim 23, further comprising:

seventh control logic means for enabling the computer to remove said write request from said command queue after completion of said write request.

25. The computer program product of claim 22, further comprising:

sixth control logic means for enabling the computer to remove said write request from said command queue if said write request is to be processed using a DMA controller.

26. The computer program product of claim 25, further comprising:

seventh control logic means for enabling the computer to signal the corresponding DMA controller in said array to transfer write data to said NVRAM.

27. The computer program product of claim 26, further comprising:

eighth control logic means for enabling the computer to write a response to a response queue indicating command completion after said write data has been transferred to said NVRAM.

28. The computer program product of claim 17, further comprising:

fourth control logic means for enabling the computer to boot the CPU on said RAID controller upon recovery from shutdown.

29. The computer program product of claim 28, further comprising:

fifth control logic means for enabling the computer to check said command queue stored in NVRAM for inline write commands.

30. The computer program product of claim 29, further comprising:

sixth control logic means for enabling the computer to issue said inline write commands to respective disks in said array upon detecting the presence of said inline write commands in said command queue.

31. The computer program product of claim 30, further comprising:

seventh control logic means for enabling the computer to complete the initialization of said RAID controller subsequent to issuing all inline write commands in said command queue.

32. The computer program product of claim 29, further comprising:

sixth control logic means for enabling the computer to complete initialization of said RAID controller upon detecting an absence of said inline write commands in said command queue.