Section 9.3. Understanding VirtualCenter Terms and Concepts

9.3. Understanding VirtualCenter Terms and Concepts

Chapter 1 introduced terms and concepts related to server virtualization, VMware-specific terms and concepts. This chapter either adds to or reinforces previously mentioned terms and concepts with the goal of this section being terms and concepts that are unique to VirtualCenter. We hope this will have us all using the same vocabulary.

9.3.1. Managed Components

VirtualCenter would have no reason to exist if it had nothing to manage. The following components are managed by VirtualCenter:

• Virtualization Platform The VMware products used to create virtual machines include ESX Server, GSX Server, and VMware Workstation.

• Host (Managed Host) These physical servers run either ESX or GSX server and actually run virtual machines.

• Virtual Machines This guest operating system, as well as its associated applications that run on virtualized hardware, runs on the ESX or GSX Server (Host).

• Datastores These are the various storage locations for associated virtual machine files. They include VMFS, SAN, and Local Storage.

9.3.2. Software Components

The software components of VirtualCenter are the underlying technologies that work together to provide the services that make VirtualCenter so good. VirtualCenter Application consists of the following software components:

• VirtualCenter Server The server service that actively communicates with the managed host and writes data to the VirtualCenter Database. This service coordinates actions with VMs and managed hosts.

• VirtualCenter Web service This optional service can be installed with VirtualCenter Server. This is a required component for third-party applications that use the VMware SDK Application programming interface.

• VirtualCenter Database This database is used to store persistent information on the status of managed hosts, VMs, and VirtualCenter users. It can be installed locally or on a remote database server.

• VirtualCenter Client Windows management interface that can be installed on a Windows desktop or server and used to manage the VirtualCenter Application.

• Virtual Center Agent This software component is installed on each managed host. It collects, communicates, and performs actions received from the VirtualCenter Server.

• VMotion A cool feature that allows running virtual machines to move from one managed host to another without a loss in service.

9.3.3. VirtualCenter Organizational Hierarchy

Table 9.1 covers the organizational hierarchy and objects that exists within VirtualCenter.

Table 9-1. VirtualCenter Containers and Objects

Container Type	What Is It For?
Server Farms	There is only one "Server Farms" group. It can contain other farm groups or farms.
Farm Group	Can be used to further organize or secure your virtual resources. It can contain other farm groups or farms.
Farm	You add your ESX Server and GSX Server Managed Host to this container. You also create virtual machine groups in this container.
Virtual Machine Group	Can contain other virtual machine groups and virtual machines.
Host	Is a member of a farm.
Virtual Machine	This represents a virtual machine in the VirtualCenter Console screen.
Discovered VMs	Special container for VMs that have been discovered on a managed host, but have not been moved to a virtual machine group.

9.3.4. Functional Components

The following components are considered the functional components of VirtualCenter that are used to accomplish tasks in VirtualCenter from the VirtualCenter client:

• Inventory The view of all monitored and managed components with VirtualCenter

• Scheduled Tasks The list of scheduled tasks and tools used to schedule those tasks

• Templates Images that are managed and can be deployed to create new virtual machines when needed

• Alarms Component that allows you to define a triggering event and perform actions

• Events Global list of events that occur in the VirtualCenter environment which can be filtered and sorted as needed