This posting will be part of my SCOM basics series and covers the key concepts of Objects and Classes.
An object is the basic unit of management in Operations Manager. An object typically represents something in your computing environment, such as a computer, a logical disk, or a database. It could also represent something more abstract, such as an application, an Active Directory domain, or a DNS zone. An object can also be referred to as an instance of a particular Class.
A class represents a kind of object, and every object in Operations Manager is considered an instance of a particular class. All instances of a class share a common set of properties. Each object has its own values for these properties which are determined when the object is discovered.
Most management packs define a set of classes that describe the different components that make up the application that is being monitored and the relationships between those classes
A target in the Operations console represents all instances of a particular class. For example, a viewlists all of the objects that are instances of the class that is used as the target class for the view, and a monitor is applied to all objects that are instances of the monitor’s target class.
Classes have two further categories. Base Classes and Hosted Classes
Every class in Operations Manager has a base class. A class has all the properties of its base class and could add more. All of the classes from the different management packs installed in your management group can be arranged in a tree with each class positioned under its base class.
When you select a class as a target that is a base class for other classes, the monitor or rule applies to all instances of each of those classes. For example, if you use Windows Operating System as the target for a monitor, then the monitor applies to all instances of Windows Client Operating System and Windows Server Operating System. This is because those two classes use Windows Operating System as their base class.
Most classes are hosted by another class. When one class hosts another, the hosting class is called the parent, and the class being hosted is called the child. Instances of the child class cannot exist without a parent.
For example, several classes are hosted by Windows Computer because they are components on a computer. It would not make sense to have a logical disk if there was no computer for the disk to be installed on. Therefore, Logical Disk is hosted by Windows Computer. This means that every instance of Logical Disk must have one instance of Windows Computer as its parent.
Note about Groups
I’ve included groups in this posting because it can be a common mistake to try and use a group as a target for a rule / monitor this can cause that rule / monitor to not function correctly as the class for a group only exists on a management server, the group will not be enumerated into it’s members from the target selection.