ConfigStoreRootPath cluster parameter is not defined

This article describes how to fix the warning/error “ConfigStoreRootPath cluster parameter is not defined” appearing in the following situations:

• When you add a Windows Server 2016 Hyper-V cluster to Veeam console.
• When you take a backup of a VM with a shared virtual disk located on the Windows Server 2016 Hyper-V cluster

In Hyper-V 2016 Microsoft implemented a possibility to share a virtual hard disk (in .vhdx or .vhds format only) between two or more VMs and use that virtual hard disk as a shared storage when building guest clusters.
 
When you decide to add a Windows Server 2016 Hyper-V cluster to Veeam console, you must decide where to store meta files created during the backup process of the VMs from the shared virtual hard disk (i.e. information about snapshot groups etc.).
 
By default, meta files location is not defined, so you need to define it manually.

1. To check the existing configuration run the following PS command on any node of the cluster:
 

Get-ClusterResource "Virtual Machine Cluster WMI" | Get-ClusterParameter ConfigStoreRootPath

By default, “value” points to a cluster volume (e.g. C:\ClusterStorage\Volume1).

Please note that this value can be set only once. After it has been populated, you cannot change it anymore. This Microsoft article provides more information.

2. Create a folder on that volume, and this folder will act as the meta files location. The folder should be available to all members of the cluster. (e.g. C:\Clusterstorage\Volume1\Hyper-V\Shared)

3. Specify the path to the newly created folder with the following commands:
 

$path = "C:\ClusterStorage\Volume1\Hyper-V\Shared"
Get-ClusterResource "Virtual Machine Cluster WMI" | Set-ClusterParameter -Name ConfigStoreRootPath -Value $path

The cluster now can be added to Veeam. If the cluster had already been added and the backup failed with the error in question, re-run the backup after setting the value.