Going down the IT rabbit hole

In November and December of 2018 Microsoft released few Windows Updates for Windows Server 2016 that caused havoc in SCVMM for Hyper-V switch management.

More info is available here: System Center Virtual Machine Manager fails to enumerate and manage Logical switch deployed on the host

I had switch management problem in two different environments and each one of them was different than the one documented on the link above. Since I didn’t have any better suspect than recent Windows Updates (and I knew about WMI repository problems), I decided to run the following PowerShell command:

Get-CimClass -Namespace root/virtualization/v2 -classname *vmm*

To my surprise and relieve above command didn’t return any object. The solution was easy – follow the instructions and re-add VMM related classes to the WMI repository:

Mofcomp “%systemdrive%\Program Files\Microsoft System Center 2016\Virtual Machine Manager\setup\scvmmswitchportsettings.mof”

Mofcomp “%systemdrive%\Program Files\Microsoft System Center 2016\Virtual Machine Manager\DHCPServerExtension\VMMDHCPSvr.mof”

Second customer that had similar switch management problem wasn’t on the latest Update Rollup for SCVMM and so we decided to first update SCVMM server and host management agents. This steps resolved their problem since agent update re-registered mof files.

One more blog post, related to SCVMM switch management that resembles closely to what I have seen (Hardware management error, Unknown error 0x8033801a, Check that WinRM is installed…): Logical\Standard Switch Deployment Failures in System Center Virtual Machine Manager 2016 (UR 6).