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Add virtual machine host fails with error 20408

I recently had a problem adding a host to a VMM server – all the obvious things had been checked. WinRM was enabled, firewall rules were in place. Service account had admin rights and DNS was correct.

Still, every time I attempted to add the host an error occurred:

“Error (20408) VMM could not get the specified instance Microsoft:{668f165d-4dae-bcb6-5007ff1fc2e8} of class http://schemas.microsoft.com/wbem/wsman/1/wmi/root/standardcimv2/MSFT_NetAdapterRssSettingData on the server server.fqdn. The operation failed with error NO_PARAM”

In this instance, the server was a 2016 one which has been upgraded from 2012 R2. The fix was bizarre. Save all VMs and remove the vswitches so that only normal physical adapters remain and then recreate the vswitches. The config was identical but clearly, something behind the scenes was wrong and recreating the vswitches worked. Retrying the same job on VMM resulted in success and the host was added to VMM.

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VMM Host not responding – WinRM Error and access is denied

If you have a Virtual Host in Virtual Machine Manager that is not responding, and forcing a manual refresh returns an error like this:

Error (2910)
VMM does not have appropriate permissions to access the resource C:\Windows\system32\qmgr.dll on the server.
Access is denied (0x80070005)

It can often be remedied by one of the following: Re-install the VMM agent, restart the virtual machine manager agent and WMI services or restart the virtual host.  It is also worth making sure your hosts are all up to date as well.

Occasionally I see a host where this doesn’t work and no matter what it, remains as “not responding” in VMM.  For me the case appears to be a broken winrm configuration.  You can be fooled into thinking winrm is setup correctly as a “winrm /quickconfig” returns as already setup, and the winrm service is running.

It looks like all the “winrm /quickconfig” command does is check that winrm has been enabled, it wont reset other possibly incorrect configurations or broken settings.

Comparing the winrm configuration and registry of a working identical host to a “not responding” host I have found the following commands will correct the deviated settings and usually results in a host that now responds to VMM.

reg add HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System /v LocalAccountTokenFilterPolicy /t REG_DWORD /d 1 /f

winrm set winrm/config/service/auth @{CredSSP=”True”}
winrm set winrm/config/winrs @{AllowRemoteShellAccess=”True”}
winrm set winrm/config/winrs @{MaxMemoryPerShellMB=”2048″}
winrm set winrm/config/client @{TrustedHosts=”*”}
winrm set winrm/config/client/auth @{CredSSP=”True”}

Be sure to run these on the effected host in an admin command prompt.

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Upgrading System Center Virtual Machine Manager 2012 SP1 to R2

The upgrade process is reasonably smooth but requires you to uninstall the SCVMM 2012 SP1 and any Hotfixes or update rollups that are in place.  You will also need to uninstall the 8.0 Microsoft ADK and install the latest 8.1 version before running setup from the Virtual Machine Manager 2012 R2 disk.  The 8.1 ADK can be found here: http://www.microsoft.com/en-gb/download/details.aspx?id=39982

Before starting gather and record the details of the existing implementation if not already documented.  For example the database server, instance name, database name and the details of the virtual machine manager service account.  You can view the current database configuration from within the VMM console.  While in the “Administration/Settings” view, click on “General” and then double click “Database Connection” While it is possible to use the local system service I would recommend creating a domain user for the service to run as with a local system service account baremetal hyper-v host deployments are not possible and you may have trouble logging in from other machines.

I would also make sure at least 10GB of free space is available on the VMM server as the 8.1 ADK is quite large.

  1. Uninstall both the VMM 2012 condole and management features. Make sure you select the option to retain the database.
  2. Take a backup of your SCVMM database.
  3. Uninstall the 8.0 ADK
  4. Install the 8.1 ADK – If you are using the online installer a large amount of data will need to be downloaded.  If this is not possible consider running the installer ahead of the upgrade and download the full install for later offline installation.
  5. Run setup from the VMM 2012 R2 disk
  6. Simply follow the wizard entering the database and service account details you recorded earlier
  7. Once setup is complete there are a few tasks left to complete: Any driver packs will need to be removed and re-added or they may not be discovered correctly.  Virtual Machine templates may need to be re-pointed to the correct operating system containing VHD.  You will also of course need to update the agents on all of your VMM managed hosts.