I plan on deploying a cluster of 2 physical servers running vSphere. The VMs in this cluster will be ran in fault tolerance mode. Can the vCenter server be ran as a appliance on the vSphere cluster, or does it require its own server separate from the cluster? Thanks!
We run ours in the cluster. We don't have too many issues.
See: http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2003790 for vecenter installation best practices
and http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&docType=kc&docTypeID=DT_KB_1_1&externalId=10087 for special considerations related to running vcenter in a virtual machine.
If you have the resources on the two hosts, run vcenter as a VM. If you are tight on resources... you could push vcenter to a physical.
It runs as an appliance on one of your hosts. The only time when you wouldn't do this is if you were running hundreds of hosts and vCenter requires more and more RAM to function.