Using external memory devices to improve system performance

• US 20060090031A1
• Filed: 10/21/2004
• Published: 04/27/2006
• Est. Priority Date: 10/21/2004
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Fortin, Michael R., Ergan, Cenk, Kirshenbaum, Alexander, Reinauer, Robert L.
• Granted Patent: US 7,490,197 B2
• Time in Patent Office: Days
• US Class Current: 711/113
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 3/0611 in relation to response time
• 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 3/0685 Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays

Abstract

The invention is directed towards a system and method that utilizes external memory devices to cache sectors from a rotating storage device (e.g., a hard drive) to improve system performance. When an external memory device (EMD) is plugged into the computing device or onto a network in which the computing device is connected, the system recognizes the EMD and populates the EMD with disk sectors. The system routes I/O read requests directed to the disk sector to the EMD cache instead of the actual disk sector. The use of EMDs increases performance and productivity on the computing device systems for a fraction of the cost of adding memory to the computing device.

Claims

1. A method to utilize an external memory device to improve performance of a computing device having a rotating storage device comprising the steps of:

detecting when the external memory device is available for use by the computing device;

populating the external memory device with a copy of a sector from the rotating storage device; and

redirecting an I/O read request from the computing device or an application for data that is stored on the sector to be read from the external memory device transparently to the computing device or the application.

2. The method of claim 1 wherein the step of populating the external memory device with a sector from the rotating storage device comprises the step of populating the external memory device with a copy of a sector from one of a hard drive and a multimedia drive.

3. The method of claim 1 wherein the step of populating the external memory device with a sector from the rotating storage device comprises the steps of:

detecting if a history of usage is available; and

populating the external memory device with a copy of a sector indicated by the history as being likely to be used.

4. The method of claim 3 further comprising the step of populating the external memory device with a copy of a sector being accessed by the computing device or the application if the history of usage is not available.

5. The method of claim 1 further comprising the step of installing a driver for the external memory device.

6. The method of claim 1 wherein the external memory device comprises a plurality of external memory devices, the method further comprising the step of prioritizing sectors to be installed on the plurality of external memory devices by populating sectors most likely to be accessed on external memory devices of the plurality of external memory devices that have a better bandwidth and latency in comparison to other external memory devices of the plurality of external memory devices.

7. The method of claim 1 further comprising the steps of:

detecting when a write operation is directed to a sector of the rotating storage device that has been copied on the external memory device;

instantiating the write operation on the sector of the rotating storage device;

copying the sector onto the external memory device after the write operation has been completed.

8. The method of claim 1 further comprising the steps of:

detecting when the external memory device is no longer available for use by the computing device; and

directing an I/O read request from the computing device or an application for data on a sector that was copied onto the external memory device to be read from the rotating storage device.

9. The method of claim 1 wherein the external memory device comprises a plurality of external memory devices, the method further comprising the steps of:

detecting when one of the external memory devices is no longer available for use by the computing device;

repopulating the remaining external memory devices with sectors from the rotating storage device if the one of the external memory devices is not the slowest external memory device of the plurality of external memory devices.

10. The method of claim 1 wherein the step of populating the external memory device with a sector from the rotating storage device comprises the steps of:

predicting which sectors are likely to be accessed; and

populating the external memory device with sectors that are likely to be accessed.

11. The method of claim 1 further comprising the steps of:

detecting when the computing device is powering down or entering hibernation;

copying sectors having configuration data into the external memory device such that the configuration data has an initialization time that is approximately equal to a spin-up time of the rotating storage device; and

initializing the configuration data in the external memory device into system memory while the rotating storage device is spinning up during at least one of a boot of the computing device and a resumption of the computing device from hibernation.

12. The method of claim 1 wherein the step of populating the external memory device with the copy of a sector from the rotating storage device includes the step of asynchronously populating the external memory device with the copy of a sector from the rotating storage device.

20. At least one computer readable medium having computer executable instructions for performing the steps of claim 1.

21. The at least one computer readable medium of claim 20 wherein the step of populating the external memory device with a sector from the rotating storage device comprises the step of populating the external memory device with a copy of a sector from one of a hard drive and a multimedia drive.

22. The at least one computer readable medium of claim 20 wherein the step of populating the external memory device with a sector from the rotating storage device comprises the steps of:

detecting if a history of usage is available; and

populating the external memory device with a copy of a sector indicated by the history as being likely to be used.

23. The at least one computer readable medium of claim 22 having further computer executable instructions for performing the step comprising populating the external memory device with a copy of a sector being accessed by the computing device or the application if the history of usage is not available.

24. The at least one computer readable medium of claim 20 having further computer executable instructions for performing the step comprising installing a driver for the external memory device.

25. The at least one computer readable medium of claim 20 wherein the external memory device comprises a plurality of external memory devices, the at least one computer readable medium having further computer executable instructions for performing the step comprising prioritizing sectors to be installed on the plurality of external memory devices by populating sectors most likely to be accessed on external memory devices of the plurality of external memory devices that have a better bandwidth and latency in comparison to other external memory devices of the plurality of external memory devices.

26. The at least one computer readable medium of claim 20 having further computer executable instructions for performing the steps comprising:

detecting when a write operation is directed to a sector of the rotating storage device that has been copied on the external memory device;

instantiating the write operation on the sector of the rotating storage device;

copying the sector onto the external memory device after the write operation has been completed.

27. The at least one computer readable medium of claim 20 having further computer executable instructions for performing the steps comprising:

detecting when the external memory device is no longer available for use by the computing device; and

directing an I/O read request from the computing device or an application for data on a sector that was copied onto the external memory device to be read from the rotating storage device.

28. The at least one computer readable medium of claim 20 wherein the external memory device comprises a plurality of external memory devices, the at least one computer readable medium having further computer executable instructions for performing the step comprising:

detecting when one of the external memory devices is no longer available for use by the computing device;

repopulating the remaining external memory devices with sectors from the rotating storage device if the one of the external memory devices is not the slowest external memory device of the plurality of external memory devices.

29. The at least one computer readable medium of claim 20 wherein the step of populating the external memory device with a sector from the rotating storage device comprises the steps of:

predicting which sectors are likely to be accessed; and

populating the external memory device with sectors that are likely to be accessed.

30. The at least one computer readable medium of claim 20 having further computer executable instructions for performing the steps comprising:

detecting when the computing device is powering down or entering hibernation;

copying sectors having configuration data into the external memory device such that the configuration data has an initialization time that is approximately equal to a spin-up time of the rotating storage device; and

initializing the configuration data in the external memory device into system memory while the rotating storage device is spinning up during at least one of a boot of the computing device and a resumption of the computing device from hibernation.

13. A system for utilizing an external memory device to improve performance of a computing device having a rotating storage device comprising:

an external memory device manager module in communication with a memory manager of the computing device and the rotating storage device, the external memory device module having at least one computer readable medium having computer executable instructions for performing the steps comprising;

detecting when the external memory device is available for use by the computing device;

populating the external memory device with a copy of a sector from the rotating storage device; and

redirecting an I/O read request from the computing device or an application for data that is stored on the sector to be read from the external memory device.

14. The system of claim 13 wherein the step of populating the external memory device with a sector from the rotating storage device comprises the steps of:

detecting if a history of usage is available; and

populating the external memory device with a copy of a sector indicated by the history as being likely to be used.

15. The system of claim 13 wherein the external memory device manager module has further computer executable instructions for performing the step comprising prioritizing sectors to be installed on the plurality of external memory devices by populating sectors most likely to be accessed on external memory devices of the plurality of external memory devices that have a better bandwidth and latency in comparison to other external memory devices of the plurality of external memory devices.

16. The system of claim 13 wherein the external memory device is remotely connected to the system.

17. The system of claim 13 wherein the rotating storage device comprises at least one of a hard drive and a multimedia drive.

18. The system of claim 17 wherein the copy of a sector is written in the format required by the multimedia drive.

19. The system of claim 13 wherein the external memory device is connected to a Universal Serial Bus 2 (USB 2) bus of the computing device.