Just noticed that one of my Windows Server 2012 R2 Hyper-V hosts was showing as Host Not Responding in the Status column for all the VMs running on it via System Center Virtual Machine Manager 2012 R2.
I tried right-clicking on the host and doing a refresh, but just got an error back in the VMM tasks list:
Error (2912) An internal error has occurred trying to contact the HV05.rcmtech.co.uk server: : . WinRM: URL: [http://hv05.rcmtech.co.uk:5985], Verb: [ENUMERATE], Resource: [http://schemas.microsoft.com/wbem/wsman/1/wmi/root/cimv2/Win32_PerfFormattedData_Tcpip_NetworkInterface], Filter:  Unknown error (0x8004100a) Recommended Action Check that WS-Management service is installed and running on server HV05.rcmtech.co.uk. For more information use the command "winrm helpmsg hresult". If HV05.rcmtech.co.uk is a host/library/update server or a PXE server role then ensure that VMM agent is installed and running. Refer to http://support.microsoft.com/kb/2742275 for more details.
So I tried stopping the WinRM service, which also required the SCVMMAgent service to be restarted. However, the WinRM service just sat at Stopping and wouldn’t die. WinRM runs within an svchost process, which is somewhat annoying, as I didn’t want to kill the other services running in that process. You can see what services are running in svchost processes by using:
In the end I killed all the wmiprvse services running on the host, which then allowed the WinRM service to stop.
I restarted it again and did another host refresh via VMM. This time I got the following error:
Error (2927) A Hardware Management error has occurred trying to contact server HV05.rcmtech.co.uk :n:CannotProcessFilter :HRESULT 0x8033801a:No instance found with given property values. . WinRM: URL: [http://hv05.rcmtech.co.uk:5985], Verb: [INVOKE], Method: [GetVersion], Resource: [http://schemas.microsoft.com/wbem/wsman/1/wmi/root/scvmm/AgentManagement] Unknown error (0x8033801a) Recommended Action Check that WinRM is installed and running on server HV05.rcmtech.co.uk. For more information use the command "winrm helpmsg hresult" and http://support.microsoft.com/kb/2742275 .
which was because I’d forgotten to restart the SCVMMAgent service. Once I’d started that I tried another host refresh, which completed successfully and the VMs are now showing as healthy again.