Event ID 21201 — Cluster

Applies To: Windows Server 2008

This is preliminary documentation and subject to change.

This aspect refers to all the events referring to clustered virtual machines.

Event Details

Product: Windows Operating System
ID: 21201
Source: Microsoft-Windows-Hyper-V-High-Availability
Version: 6.0
Message: The virtual network switch '%1' was not found.


Check virtual network switch

Ensure that there is a virtual network switch with the same name on the target machine.

To check the virtual switch names using the Hyper-v Manager:

1. Open the Hyper-V Manager

2. Click the target machine in the list of machines

3. Click Virtual Network Manager in the Actions menu

To check virtual switch names using PowerShell, run the following PowerShell script:

$HyperV = "HyperV Name"$NameSpace = "Root\Virtualization"get-wmiobject -Name $NameSpace -Com $HyperV -Class Msvm_InternalEthernetPort | Select DeviceID,ElementName,MaxDataSizeget-wmiobject -Name $NameSpace -Com $HyperV -Class Msvm_ExternalEthernetPort | Select DeviceID,ElementName,MaxDataSize,IsBoundget-wmiobject -Name $NameSpace -Com $HyperV -Class Msvm_SyntheticEthernetPort | Select DeviceID,ElementName,MaxDataSize$VSwitch = get-wmiobject -Name $NameSpace -Com $HyperV -Class Msvm_VirtualSwitch $VSwitch | Select Name,ElementName,Ports


All the clustered resources are in a healthy state and failover operations are completing successfully.