Windows 2012 Hyper-V VMs enters a paused state or a CSV volume goes offline during back-up

A serious issue when backing up CSV 2.0 volumes. Host-based backups could bring down most of the VMs on the cluster. This can be a serious show stopper if you plan to migrate to Windows 2012 Hyper-V

When creating a back-up of a Windows 2012 Hyper-V CSV  volume you might get the following error in your cluster log.

Event id: 5120 Cluster Shared Volume xxxx is no longer available on this node because of 'STATUS_CLUSTER_CSV_AUTO_PAUSE_ERROR(c0130021)'. All I/O will temporarily be queued until a path to the volume is reestablished.

• You enable the Cluster Shared Volumes (CSV) feature on a Windows Server 2012-based failover cluster.
• You create a virtual machine on a CSV volume on a cluster node.
• You start the virtual machine.
• You try to create a backup of the virtual machine on the CSV volume by using Microsoft System Center Data Protection Manager (DPM).

In this scenario, one of the following issues occurs:

• The backup is created, and the virtual machine enters a paused state.
• The CSV volume goes offline. Therefore, the virtual machine goes offline, and the backup is not created.
• VMs stop responding while the backups runs

There is a hotfix available from Microsoft unfortunately it looks like this doesn’t solve the issue. In addition after applying this hotfix there seemed to be a severe memory leak on the node storage owner.

More info and a workaround available on the Technet Forum thread.

More information also available the Microsoft support article: Issues that occur after you deploy System Center 2012 DPM SP1.