Direct Virtual Center inventory and monitoring enables multiple virtual machines to be more efficiently inventoried from one single point instead of inventorying them individually.
Monitoring through the Virtual Center provides different information than monitoring a virtual machine directly, because it is a picture of the virtual machine resource usage as detected by the Virtual Center and ESX host. This is more accurate than a virtual machine reporting on its own resource utilization. For example, a virtual machine using 90% of its allotted processing capabilities reports its processor usage as 90%. In reality, it might have been allocated only 30% of the host processor capabilities. This difference can only be detected by monitoring through the Virtual Center, which reports what percentage of the host processor a virtual machine is using.
This difference has become more and more useful as data centers place emphasis on managing and optimizing virtual machine usage as opposed to merely consolidating physical servers onto virtual machines.
When a Virtual Center is inventoried, its associated machines are displayed in the Data Center Explorer in a hierarchy that reflects the VMware Virtual Infrastructure Client hierarchy, including all data centers, folders, clusters and pools.
Figure 8-1 Data Center Explorer and VMware Virtual Infrastructure Client Comparison
Inventorying a Virtual Center discovers all the machines that are part of the Virtual Center, so that they can then be inventoried and monitored. When a virtual machine is inventoried through the Virtual Center, it shows up as inventoried both as a node in the Virtual Center, and as an inventoried machine under All in the Data Center Explorer. Either node can subsequently be used to initiate monitoring.
You can right-click a cluster in a Virtual Center to view its properties, which are set in the Virtual Center.
When a virtual machine that is part of a Virtual Center is monitored, certain values, such as Processor Time, are collected both directly from the virtual machine and through the Virtual Center. Values that are being collected through the Virtual Center are prefixed with VC, for example VC_ProcessorTime.
See Section 3.7.2, Virtual Center for information about how to inventory a Virtual Center.