About the Common Information Model

This section provides a brief introduction to basic CIM terms and concepts as they are used in the Solaris WBEM Services product. For more information on CIM, see Appendix A, Common Information Model (CIM) Terms and Concepts.

CIM is an object-oriented information model for describing managed resources such as disks, CPUs, and operating systems. A CIM object is a representation, or model, of a managed resource, such as a printer, disk drive, or CPU. CIM objects can be shared by any WBEM-enabled system, device, or application.

Basic CIM Elements

CIM objects with similar properties and purposes are represented as CIM classes. Properties are attributes that describe a unit of data for a class. An instance is a representation of a managed object that belongs to a particular class. Instances contain actual data. For example, Solaris_ComputerSystem is a CIM class that represents a computer running the Solaris operating environment. The Solaris software running your workstation is an instance of the Solaris_OperatingSystem class. ResetCapability and InstallDate are examples of properties of the Solaris_ComputerSystem class.

CIM classes are grouped into meaningful collections called schemas. A schema is a group of classes with a single owner. A class must belong to only one schema. Schemas are used for administration and class naming. All class names must be unique within a particular schema. The schema name is the determining factor in differentiating classes and properties from others that may have the same name. The naming of schema, class, and property follow this syntax:

Schemaname_classname.propertyname

The CIM Models

The Common Information Model categorizes information from general to specific. Specific information, such as a representation of the Solaris environment, extends the model. CIM consists of the following three layers of information:

• Core Model - A subset of CIM not specific to any platform.

• Common Model - Information model that visually depicts concepts, functionality, and representations of entities related to specific areas of network management, such as systems, devices, and applications.

• Extensions - Information models that support the CIM Schema and represent a very specific platform, protocol, or corporate brand.

Collectively, the Core Model and the Common Model are referred to as the CIM Schema.

The Core Model

The Core Model provides the underlying, general assumptions of the managed environment--for example, that specific, requested data must be contained in a location and distributed to requesting applications or users. These assumptions are conveyed as a set of classes and associations that conceptually form the basis of the managed environment. The Core Model is meant to introduce uniformity across schemas intended to represent specific aspects of the managed environment.

For applications developers, the Core Model provides a set of classes, associations, and properties that can be used as a starting point to describe managed systems and determine how to extend the Common Model. The Core Model establishes a conceptual framework for modeling the rest of the managed environment.

The Core Model provides classes and associations to extend specific information about systems, applications, networks, devices, and other network features through the Common Model and extensions.

The Common Model

Areas of network management depicted in the Common Model are independent of a specific technology or implementation but provide the basis for the development of management applications. This model provides a set of base classes for extension into the area of five designated technology-specific schemas: Systems, Devices, Applications, Networks, and Physical.

CIM Extensions

Extension schemas are built upon CIM to connect specific technologies to the model. By extending CIM, a specific operating environment such as Solaris can be made available to a greater number of users and administrators. Extension schemas provide classes for software developers to build applications that manage and administer the extended technology. The Solaris Schema is an extension of the CIM Schema.