If you are using software VSS providers, we recommend that you use hardware providers. For more information go to http:/ ...

If you are using software VSS providers, we recommend that you use hardware providers. For more information go to [http://go.microsoft.com/fwlink/?LinkId=179952] .
If hardware VSS provider is already installed on the node, check the status of CSVs used by this virtual machine from the Cluster Administration Console and re-enable direct I/O for the CSV. Then retry the operation.