Windows Management Instrumentation 25
Windows Management Instrumentation

WMI Overview

Microsoft® Windows ® Management Instrumentation (WMI) is Microsoft’s
implementation of the Web-Based Enterprise Management (WBEM) effort.
It is implemented on Microsoft Windows platforms.
There are two components to WMI. In the Dell™ OpenManage™ Client
Instrumentation (OMCI) architecture (see Figure1-1), both the components
are represented by the Microsoft WMI Object Manager. The first component
is the Common Information Mod el (CIM) Object Manager (CIMOM), which
is the interface and manipulation point for CIM objects and information.
It acts as a facilitator in gathering information and manipulating object
properties. Microsoft has implemented this component as the Windows
management (winmgmt) service. The CIMOM is a software middle layer that
mediates interactions between high-level management applications and the
lower levels of instrumentation, such as OMCI and other providers. The
CIMOM ensures that data supplied by providers is presented to management
applications in a uniform and provider-independent way. TheCIMOM does
this, in part, by using the Component Object Model (COM) Application
Programming Interface (API) for communication with providers and
management applications.
The second WMI component is the repository. The repository is a binary file
where the CIMOM stores management data. Such data includes information
from the compiled Managed Object Format (MOF) file(s), including the
CIM class definitions, properties, qualifiers, and hierarchical relationships.
Instance data, as it becomes available, is also stored here.

WMI Security

WMI provides for user authentication before granting access to CIM data
and methods. Access privileges are enforced by Distributed Component
Object Model (DCOM) security and the CIMOM. Access, whether full