Granted Patent B2

US 8,473,648 · App. 12/969,601 · Granted Jun 25, 2013

Inventors: Madhukar Gunjan Chakhaiyar (Gaya, IN); Mahmoud K Jibbe (Wichita, KS); Dhishankar Sengupta (Yelachanahalli, IN); Himanshu Dwivedi (Bangalore, IN)

Assignee: LSI Corporation

Abstract

Claims (62)

1. A method for I/O path virtualization between a RAID controller and an environment service module (ESM) in a storage area network (SAN), comprising:

identifying a type of I/O request by an input/output (I/O) control engine upon receiving an I/O request from a host computer via a RAID controller;

assigning a priority to the received I/O request based on the type of I/O request by the I/O control engine;

interrupting processing of the prioritized I/O request by the I/O control engine, wherein interrupting the processing of the prioritized I/O request comprises:

determining whether a host I/O time out value associated with the received I/O request is close to a predefined host I/O time out threshold value by the I/O control engine;

if so, sending the prioritized I/O request to an associated disk drive in a drive tray via a plurality of solid state drive (SSD) buffer queues (SBQs) for execution by the I/O control engine; and

if not, interrupting processing of the prioritized I/O request by the I/O control engine;

separating the prioritized I/O request into a command I/O request or a status request; and

sending the separated command I/O request or the status request to an associated queue in the plurality of SBQs in the I/O control engine.

2. The method of claim 1 , wherein assigning the priority to the received I/O request based on the type of I/O request comprises:

assigning the priority to the received I/O request based on priority rules/policies that are configurable by a user as a function of application and/or workload.

3. The method of claim 1 , further comprising:

determining whether the assigned priority to the received I/O request has a higher priority;

if so, sending the prioritized I/O request to the associated disk drive in the drive tray via the plurality of SBQs for execution by the I/O control engine; and

if not, sending the command I/O request or status request to queue in an associated one of the plurality of SBQs by the I/O control engine.

4. The method of claim 3 , wherein determining whether the assigned priority to the received I/O request has a higher priority, comprises:

determining whether the assigned priority to the received I/O request has a higher priority based on a look-up table by the I/O control engine.

5. The method of claim 1 , wherein the command I/O request comprises I/O request selected from the group consisting of a read I/O request and a write I/O request.

6. The method of claim 1 , wherein the status request comprises I/O request selected from the group consisting of an acknowledge request, a status request, and an error recovery level request.

7. A non-transitory computer-readable storage medium for I/O path virtualization between a RAID controller and an environment service module (ESM) in a storage area network (SAN), having instructions that, when executed by a computing device causes the computing device to:

identify a type of I/O request by an input/output (I/O) control engine upon receiving an I/O request from a host computer via a RAID controller;

assign a priority to the received I/O request based on the type of I/O request by the I/O control engine;

interrupt processing of the prioritized I/O request by the I/O control engine, wherein interrupting the processing of the prioritized I/O request comprises:

determining whether a host I/O time out value associated with the received I/O request is close to a predefined host I/O time out threshold value by the I/O control engine;

if so, sending the prioritized I/O request to an associated disk drive in a drive tray via a plurality of solid state drive (SSD) buffer queues (SBQs) for execution by the I/O control engine; and

if not, interrupting processing of the prioritized I/O request by the I/O control engine;

separate the prioritized I/O request into a command I/O request or a status request; and

send the separated command I/O request or the status request to an associated queue in the plurality of SBQs in the I/O control engine.

8. The non-transitory computer-readable storage medium of claim 7 , wherein assigning the priority to the received I/O request based on the type of I/O request comprises:

assigning the priority to the received I/O request based on priority rules/policies that are configurable by a user as a function of application and/or workload.

9. The non-transitory computer-readable storage medium of claim 7 , further having instructions to:

determine whether the assigned priority to the received I/O request has a higher priority;

if so, send the prioritized I/O request to the associated disk drive in the drive tray via the plurality of SBQs for execution by the I/O control engine; and

if not, send the command I/O request or status request to queue in an associated one of the plurality of SBQs by the I/O control engine.

10. The non-transitory computer-readable storage medium of claim 9 , wherein determining whether the assigned priority to the received I/O request has a higher priority, comprises:

determining whether the assigned priority to the received I/O request has a higher priority based on a look-up table by the I/O control engine.

11. The non-transitory computer-readable storage medium of claim 7 , wherein the command I/O request comprises I/O request selected from the group consisting of a read I/O request and a write I/O request.

12. The non-transitory computer-readable storage medium of claim 7 , wherein the status request comprises I/O request selected from the group consisting of an acknowledge request, a status request, and an error recovery level request.

13. A storage area network (SAN), comprising:

one or more host computers;

an environment service module (ESM), wherein the ESM comprises:

an input/output (I/O) control engine including a plurality of solid state drive (SSD) buffer queues (SBQs); and

one or more drive trays including disk drives coupled to the I/O control engine; and

a RAID controller coupled between the one or more host computers and the ESM,

wherein the I/O control engine identifies a type of I/O request upon receiving an I/O request from one of the one or more host computers,

wherein the I/O control engine assigns a priority to the received I/O request based on the type of I/O request,

wherein the I/O control engine interrupts processing of the prioritized I/O request,

wherein the I/O control engine determines whether a host I/O time out value associated with the received I/O request is close to a predefined host I/O time out threshold value, interrupts processing of the prioritized I/O request if the host I/O time out value is not close to the defined host I/O time out threshold value, and sends the prioritized I/O request to associated disk drive in a drive tray via the plurality of SBQs for execution by the I/O control engine if the host I/O time out value is close to the defined host I/O time out threshold value,

wherein the I/O control engine separates the prioritized I/O request into a command I/O request or a status request, and

wherein the I/O control engine sends the command I/O request or status request to associated queues in the plurality of SBQs in the I/O control engine.

14. The SAN of claim 13 , wherein the I/O control engine further comprises:

a frame identification logic engine;

a priority rules/policies engine and timer;

a direct memory access (DMA) interrupt logic engine coupled to the priority rules/policies engine and timer and the frame identification logic engine;

an I/O path logic engine coupled to the frame identification logic engine and the DMA interrupt logic engine;

a status path module coupled to the I/O path logic engine;

a command path module coupled to the I/O path logic engine, wherein the status path module and the command path module are communicatively coupled to the plurality of SBQs and associated drive channels; and

a plurality of drive trays coupled to the associated drive channels, wherein the frame identification logic engine identifies the type of I/O request upon receiving the I/O request from one of the one or more host computers via the RAID controller, wherein the priority rules/policy engine and timer assigns the priority to the received I/O request based on the type of I/O request, wherein the DMA interrupt logic engine interrupts processing of the prioritized I/O request based on the type of I/O request, wherein the I/O path logic engine splits the prioritized I/O request into the command I/O request or the status request, and wherein the command path module and the status path module sends the command I/O request and the status request, respectively, to associated SBQs.

15. The SAN of claim 14 , wherein the time associated with the priority rules/policies engine and timer determines whether the host I/O time out value associated with the received I/O request is close to the predefined host I/O time out threshold value, wherein the DMA interrupt logic engine interrupts processing of the prioritized I/O request if the host I/O time out value is not close to the defined host I/O time out threshold value, and wherein the I/O path logic engine sends the prioritized I/O request to the associated disk drive in the drive tray via the plurality of SBQs for execution by the I/O control engine if the host I/O time out value is close to the defined host I/O time out threshold value.

16. The SAN of claim 14 , wherein the priority rules/policies engine and timer assigns the priority to the received I/O request based on priority rules/policies that are configurable by a user as a function of application and/or workload.

17. The SAN of claim 16 , wherein the I/O path logic engine determines whether the assigned priority to the received I/O request has a higher priority, wherein the I/O path logic engine sends the prioritized I/O request to an associated disk drive in the drive tray via the plurality of SBQs for execution by the I/O control engine if the assigned priority to the received I/O request has the higher priority, and wherein the I/O path logic engine sends the command I/O request or status request to respective queues in one of the plurality of SBQs by the I/O control engine if the assigned priority to the received I/O request does not have a higher priority.

18. The SAN of claim 17 , wherein the priority rules/policies engine and timer determines whether the assigned priority to the received I/O request has a higher priority based on a look-up table.

Assignments (8)

Continuity (1)