SOLID STATE STORAGE SUBSYSTEM THAT MAINTAINS AND PROVIDES ACCESS TO DATA REFLECTIVE OF A FAILURE RISK

• US 20090204852A1
• Filed: 02/07/2008
• Published: 08/13/2009
• Est. Priority Date: 02/07/2008
• Status: Active Grant

• Current Assignee: JP Morgan Chase Bank, N.A. (JP Morgan Chase & Co)
• Original Assignee: SiliconSystems, Inc. (Western Digital Corporation)
• Inventors: Diggs, Mark S., Merry, David E. JR.
• Granted Patent: US 8,078,918 B2
• Time in Patent Office: Days
• US Class Current: 714/42
• CPC Class Codes: G06F 11/008 Reliability or availability analysis

Abstract

A storage subsystem is disclosed that maintains (a) statistics regarding errors detected via an ECC (error correction code) module of the storage subsystem; and/or (b) historical data regarding operating conditions experienced by the storage subsystem, such as temperature, altitude, humidity, shock, and/or input voltage level. The storage subsystem, and/or a host system to which the storage subsystem attaches, may analyze the stored data to assess a risk of a failure event such as an uncorrectable data error. The results of this analysis may be displayed via a user interface of the host system, and/or may be used to automatically take a precautionary action such as transmitting an alert message or changing a mode of operation of the storage subsystem.

Claims

1. A storage subsystem, comprising:

a solid-state, non-volatile memory array organized into a plurality of sectors;

a connector for attaching the storage subsystem to the host system; and

a controller configured to write data to and read data from the non-volatile memory array in response to commands received from a host system, said controller configured to generate and store data on sector write operations, and to use the ECC data to check for and correct errors on sector read operations;

wherein the storage subsystem is configured to maintain statistical data reflective of a rate at which errors are detected on said sector read operations, and to provide said statistical data to the host system via said connector, the storage subsystem thereby enabling the host system to monitor a health of the storage subsystem.

2. The storage subsystem of claim 1, wherein the statistical data comprises a first value that indicates a number of sector write operations performed, and a second value that indicates a total number of errors corrected.

3. The storage subsystem of claim 2, wherein the statistical data further comprises a plurality of counter values, each of which corresponds to a different respective number of bits errors that can occur on a sector read operation.

4. The storage subsystem of claim 1, wherein the statistical data comprises a value that represents a bit error rate of the storage subsystem.

5. The storage subsystem of claim 1, wherein the controller is configured to analyze the statistical data to assess a risk of a failure event.

6. The storage subsystem of claim 5, wherein the controller is configured to modify a mode of operation of the storage subsystem when said risk of a failure event reaches a threshold level, to thereby reduce a likelihood of a failure event occurring.

7. The storage subsystem of claim 1, wherein the controller implements an Advanced Technology Attachment (ATA) command set, and implements at least one vendor-specific command that enables the host system to retrieve the statistical data.

8. The storage subsystem of claim 1, in combination with executable code configured to run on the host system, said executable code configured to display at least some of said statistical data, and/or a risk indicator derived therefrom, on a display of the host system.

9. The storage subsystem of claim 1, wherein the controller maintains said statistical data in a restricted area of the non-volatile memory array.

10. The storage subsystem of claim 1, further comprising a sensor that senses and at least one type of environmental condition, wherein the controller is configured to store measurement values obtained from the sensor in the non-volatile memory array, and to provide said measurement values to the host system via the connector.

11. The storage subsystem of claim 10, wherein the controller is further configured to detect, and store data regarding, correlations between environmental conditions sensed by said sensor and errors detected via said ECC checking.

12. The storage subsystem of claim 10, wherein the controller is further configured to maintain, and output to the host system, data regarding an amount of time the storage subsystem has been powered up.

13. The storage subsystem of claim 10, wherein the controller is further configured to maintain, and output to the host system, data regarding a stability of a power signal received from the host system.

14. A method performed by a storage subsystem, the method comprising:

generating and storing error correction code (ECC) data descriptive of write data received by the storage subsystem from a host system, and storing said write data and ECC data in a non-volatile solid state memory array;

performing ECC checking of said write data and ECC data when the write data is subsequently read from the non-volatile solid state memory array, said ECC checking performed by an ECC module of the storage subsystem;

maintaining statistical data in said storage subsystem reflective of a rate at which errors are detected by the ECC module; and

outputting at least some of said statistical data to the host system.

15. The method of claim 14, further comprising programmatically analyzing the statistical data to assess a risk of a storage subsystem failure.

16. A storage subsystem, comprising:

a solid-state non-volatile memory array organized into a plurality of sectors;

a connector for attaching the storage subsystem to the host system;

a controller configured to write data to and read data from the non-volatile memory array in response to commands received from a host system; and

at least one sensor that generates measurements of one or more environmental conditions;

wherein the controller is configured to output measurement data reflective of said measurements to the host system via said connector to enable the host system to assess a risk of a storage subsystem failure event.

17. The storage subsystem of claim 16, wherein the controller maintains historical measurement data reflective of said measurements in the non-volatile memory array, and outputs said historical measurement data to the host system.

18. The storage subsystem of claim 16, wherein the controller implements a standard set of ATA (Advanced Technology Attachment) commands, and additionally implements at least one non-standard command that enables the host system to retrieve said measurement data.

19. The storage subsystem of claim 16, wherein the controller is further configured to analyze the measurement data to assess a risk of a storage subsystem failure.

20. The storage subsystem of claim 16, wherein the controller is further configured to detect, and store data reflective of, correlations between error conditions and environmental conditions.

21. The storage subsystem of claim 16, wherein the at least one sensor comprises a temperature sensor.

22. The storage subsystem of claim 16, wherein the at least one sensor comprises an altitude sensor.

23. The storage subsystem of claim 16, wherein the at least one sensor comprises a shock sensor.

24. The storage subsystem of claim 16, wherein the at least one sensor comprises a humidity sensor.

25. The storage subsystem of claim 16, wherein the controller is further configured to maintain, and to output to the host, data regarding a stability of a power signal received from the host system.