Chapter 13. Windows Management and Instrumentation

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CHAPTER OBJECTIVES

WMI: The Industry Picture
The WMI Architecture
WMI Summary
Conventional Driver Event Logging
Summary

Device drivers can be written to report their performance and reliability statistics. For example, it is useful for a network driver to track the number of corrupted packets received. Devices that start to perform erratically should be identified before they fail completely.

Overall device and driver performance rates are vital pieces of information to analyze and improve system performance. Tracking and reporting such instrumentation data begins at the driver level.

Another separate but common requirement is that devices and drivers need a mechanism for dynamic configuration. Traditionally, drivers use Control Panel applets and private IOCTLs to provide this facility.

The WDM driver model includes the capability for standardizing the collection, storage, and reporting of instrumentation data the Windows Management and Instrumentation (WMI) interface. Drivers that choose to participate in the WMI scheme can collect performance and reliability data in a standardized way for applications to obtain.

The facility also provides a standardized way that clients can use to set a driver state for the purpose of device configuration. A driver can export specialized methods that client applications can invoke (almost) directly.

This chapter starts by describing the relationship of WMI to industry standards for similar functionality. The steps necessary to incorporate WMI into a driver are then presented along with an example of a WMI-enabled driver. Finally, the chapter covers the conventional mechanism of sending event messages to the Windows 2000 event log.

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