VSS Error Event 8194 on Windows Server 2012 Failover Cluster

In this case I was running Windows Server 2012 Hyper V Failover Cluster with CSV, and I was trying to backup the nodes from cluster using DPM 2012 SP1 RU 2. I have scheduled BMR system protection to all cluster member nodes. The backup of nodes was finishing successfully without any errors on DPM server. But, on all cluster nodes application log was having error logs 8194 from VSS source :

Volume Shadow Copy Service error: Unexpected error querying for the IVssWriterCallback interface. hr = 0x80070005, Access is denied.
This is often caused by incorrect security settings in either the writer or requestor process.
Gathering Writer Data
Writer Class Id: {e8132975-6f93-4464-a53e-1050253ae220}
Writer Name: System Writer
I have opened support case with Microsoft, and support engineer has confirmed that this behavior is bug. This behavior will probably not be changed, and should be ignored.


  1. Hello Vladimir,

    We're also experiencing this issue. Are the VM's on your cluster sucessfully backupped? In our case (we use the hardwareprovider from our SAN vendor to snapshot the CSV) the backups of the VM's only succeed for the host which initiated the snapshot. The VM's on the other hosts fail to backup. Does this also happen on your cluster?


  2. Hi Frans,

    All VMs are backed up successfully, and I'm using software VSS provider. I'm experiencing this error only when I'm trying to backup hosts (cluster nodes) with system protection from DPM. On DPM server there are no error logs.


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