I have an ESXi host running a Windows 2008 R2 server VM with vCenter installed.
Upon joining the Host to vCenter, suddenly I could not log directly onto the host with the vSphere client using my original root username/password.
The root user/pass works in console just fine, but get "insufficient privileges" when I try to use the vSphere client.
The problem being the power went out, turning off the vCenter VM (and the rest [Active Directory]), so now I can't connect to vCenter to start my virtual machine's again nor can I connect directly to the host.
What are my options to at least get the vCenter VM started again?
Are your VMs set to startup on Power on? If yes, you should be able to reboot the physical server to bring the virtual hosts back up.
This would be found on the configuration tab for each ESXi host in the Vsphere console under "Software> Virtual Machine Startup/Shutdown". You'd then click on properties in the top right corner and select "allow virtual machines to start and stop automatically with the system".