Cloudtidings.com

If you are using a hardware VSS provider, you can back up multiple virtual machines from the same CSV/node in the cluster.

To allow a maximum of three backups to run concurrently on each node, specify the number of concurrent backups that can run from a node.

Set the following registry key:

Key
HKLMSoftwareMicrosoftMicrosoft Data Protection Manager2.0ConfigurationMaxAllowedParallelBackups

Value Microsoft Hyper-V

Data 3

Type DWORD

Microsoft does not recommend that you do not use a value greater than 3 for optimal performance