Hyper-V backup fails with error "Failed to find shadowed path"

Hyper-V backups fail when a 3rd party VSS hardware provider is used in an environment where the shared shadow feature is enabled.

Symptoms

Hyper-V backups fail when a 3rd party VSS hardware provider is installed on Hyper-V nodes.

Causes

In V11, the shared shadow feature is enabled by default. If a 3rd party VSS hardware provider is installed on Hyper-V nodes in an environment where shared shadows are enabled, backups might fail.

Resolution

To resolve this issue, take one of the following actions for all Hyper-V nodes:

• Create the Virtual Server\VSSProvider additional setting and set the string value to 400a2ff4-5eb1-44b0-8a05-1fcac0bcf9ff. This setting forces backups to use the Microsoft CSV provider for backups.
• Create the bCreateSharedShadow additional setting and set the integer value to 0 to disable the shared shadow feature.