The design decision on whether or not a Windows-installable vCenter Server must reside on a physical or virtual machine has been around as long as vCenter Server and virtualization itself.

Some vSphere administrators are concerned that if a virtual vCenter Server goes down, they would lose all centralized management of the virtual platform. This is true, however, if vCenter Server is down, that does not mean that the hosts and virtual machines are affected. However, if your vCenter is a virtual machine in a HA / DRS management cluster, it must be started back up very quickly on another host. In addition, with a virtualized vCenter Server, you can take advantage of advanced vSphere features, such as snapshots, vSphere vMotion, and Storage vMotion.

Another consideration is how vCenter Server has changed and will change in future. As we have seen already, there is now the option of taking a scale-out approach to the vCenter Server infrastructure by distributing the Platform Services Controller onto a different Windows installation, and in most instances, this would not be scalable in the physical world. Also, consider that the vCenter Server Appliance is gaining strength and is likely to be the primary deployment mechanism for vCenter Server very soon.

For these reasons, vCenter Server is typically deployed as a virtual machine and as our goal is to achieve 100 percent server virtualization, vCenter Server is no exception. If a physical vCenter Server is deployed, list it as a risk and a single point of failure for the service owner.