Note: This article is based on VMM 2008  and might not apply to VMM 2012 (R2)

This article includes information about how to troubleshoot why some virtual machines have the “”Unsupported Cluster Configuration” status displayed in the System Center Virtual Machine Manager (VMM) console. To view the reason that a highly-available virtual machine (HAVM) is in the “Unsupported Cluster Configuration” state, follow these steps:

1. In the VMM console, click Virtual Machines.
2. Right-click the virtual machine, and then click Properties.
3. On the Hardware Configuration tab, under Advanced, click Availability.

If the virtual machine is in an Unsupported Cluster Configuration state, the Details area displays the error that placed the virtual machine in that state. The following screenshot (courtesy of Mike Briggs – click link to see his blog) shows an example of a virtual machine that is currently in this state.  (Note that you may also want to compare any other virtual machines that are in this state to see if the causes are the same.)  

 

The following situations can cause the “Unsupported Cluster Configuration” status: Note The original list of causes in this article was copied from the TechNet Library. To view the official Microsoft source documentation, see Creating and Managing Highly Available Virtual Machines in VMM.

• The virtual machine is on a non-Cluster Shared Volume (CSV) LUN that contains more than one virtual machine.
  
  If you have configured highly-available virtual machines (HAVMs) in Hyper-V to share the same LUN, and the LUN is not on a CSV, you must update the virtual machine configurations in Failover Cluster Management and in Hyper-V so that each resides on its own unshared LUN.

• The virtual machine is using non-clustered storage.
  
  If the HAVM is stored on system drive C: or any disk that is not clustered, the virtual machine is placed in the “Unsupported Cluster Configuration” state. To resolve this issue, ensure that all files and pass-through disks that belong to the virtual machine reside on clustered disks.

• One or more virtual network adapters on the virtual machine are not connected to a common virtual network.
  
  If the virtual networks on all hosts in the host cluster do not have identical settings, a highly-available virtual machine (HAVM) that is connected to such a virtual network might lose connectivity when it is migrated or fails over to another cluster node. Virtual networks that have identical settings are referred to as common virtual networks. To find the common virtual networks for a host cluster, in the VMM Administrator Console, view the Networks tab in the host cluster properties. To configure virtual networks on the hosts, use the Networking tab in host properties. For more information about configuring virtual networks, see How to Add or Modify Virtual Networks on a Host.
  
  For a virtual network to be considered common by VMM and available to HAVMs on a host cluster, each virtual network in the host cluster must meet the following requirements:
  • The virtual network name must be identical on each host in the cluster. In VMM 2008, virtual networks are recognized as common virtual networks only if the network names match in terms of name (spaces matter) and case (i.e. it is case sensitive). In VMM 2008 R2, the case-sensitive restriction was removed. Therefore, when VMM 2008 R2 identifies common virtual networks, the network name matching is not case-sensitive.
  • The host network adapters to which the virtual network is attached on each host in the cluster must have the same location.
  • The virtual network must have the same tag on each host in the cluster.

The following screenshot shows the location of these settings (copied with minor alterations from the posting Unsupported Cluster Configuration – Virtual Networks on Jonathan’s Virtual Blog).

After you update the virtual network configurations on all nodes, refresh the cluster to ensure that each virtual network is detected as common. Then check the Networks tab in the host cluster properties to verify that the networks have been added to it. PowerShell For a PowerShell script that you can use to check the network configuration, see the article Unsupported Cluster Configuration – Virtual Networks on Jonathan’s Virtual Blog.

• In VMM 2008, an ISO image is attached to HAVMs. (This issue was resolved in VMM 2008 R2.)
  
  Often, the ISO image will be at the path C:\Windows\System32\vmguest.iso. To resolve this issue, remove the ISO image by using Hyper-V Manager. Then, by using the VMM Administrator Console, use the Repair action to refresh the virtual machine. To do this, right-click the virtual machine, click Repair, and then click Ignore.

• A VMware HAVM is connected to a port group that does not exist on all nodes of the host cluster.
  
  On host clusters that VMM is managing, each port group must be configured on all ESX Server hosts in the cluster. If a virtual machine is configured with a port group that is not common to all hosts, the virtual machine has an “Unsupported Cluster Configuration” status.

• The virtual machine is configured to use multiple GPT pass-through disks.
  
  If the virtual machine is configured to use multiple GPT pass-through disks, please review knowledge base article 2505398. 

• The virtual machine is configured to use a GPT pass-through disk on a SAS storage array.
  
  If the virtual machine is configured to use a GPT pass-through disk on a SAS storage array, please review knowledge base article 2525103.