Deployment Planning for Microsoft Hyper-V

Deployment for the Virtual Server Agent (VSA) for Microsoft Hyper-V can include the following components:

  • The Virtual Server Agent can be installed on one or more machines, so that those machines can serve as VSA proxies. A VSA proxy manages backup and restore operations for guest VMs in your environment, eliminating the need to install agents on guest VMs.

    The Virtual Server Agent can be deployed on a standalone Hyper-V server or a node in a Hyper-V cluster. Multiple VSA proxies can provide load distribution and load balancing to improve the backup and restore performance.

  • MediaAgents can be deployed on physical machines or virtual machines to manage the transmission of data between clients and backup media.
  • You can configure application-aware backups using the Virtual Server Agent to protect application data without installing guest agents on virtual machines.

    When necessary, guest agents for file systems, applications, or databases can be deployed on guest VMs to support backup and restore operations, but in most cases the Virtual Server Agent is sufficient.


  • To use the Commvault Changed Block Tracking (CBT) feature for Hyper-V hosts or clusters that are running Windows Server 2012 R2, install the VSA on all Hyper-V nodes in a cluster. If you are not using the CommvaultCBT feature with Windows Server 2012 R2, install the VSA only on the nodes that will provide backup and recovery services.
  • A cluster can include Nano Server nodes provided that at least one node in the cluster is running Windows Server 2016 (Data Center Edition recommended) and has the Virtual Server Agent installed. The Enterprise server can perform remote backups for virtual machines running on Nano Server nodes if the virtual machines reside on CSV or SMB storage.

Using VSA Proxy for Cluster Shared Volumes

On Windows 2012 R2 and later deployments, a Hyper-V node with VSA installed can back up any VMs in the same cluster if the VMs reside on a Clustered Shared Volumes (CSV) storage that is directly connected to the cluster. At least one node in the cluster must have VSA installed, and only VSA client nodes that manage backups are added to the virtual server instance for the cluster. Any VSA client that is added on the virtual server instance can manage a set of VMs on CSV storage for backups. For more information on Cluster Shared Volumes, see Configuring Cluster Shared Volumes.

You can use VSA proxies for streaming backups and IntelliSnap backups.

Any Hyper-V client nodes that host virtual machines on local dedicated storage (rather than cluster shared storage) must have the VSA installed; VMs on local storage cannot be backed up by a different VSA client node.

The first available VSA client on the virtual server instance acts as a coordinator node for backups in the cluster. The coordinator node engages VSS to create a shadow of the entire CSV, including its own VMs and VMs hosted on other nodes if the VMs reside on CSV storage. VMs can be quiesced and backed up from the shadow without affecting production VMs. The CSV Writer handles communications with other nodes.

Hyper-V node sharing provides the following advantages:

  • The coordinator node can delegate data protection operations to other VSA client nodes in the cluster.
  • You can add and protect new nodes without reconfiguring the virtual server instance.
  • The number of VSS shadows that need to be created is minimized.
  • Greater host density is possible.

Note: To enhance performance, ensure that the VSA proxy owns the CSV where virtual machines reside. Using a VSA proxy with ownership of the CSV enables data protection operations to read directly from the CSV rather than redirecting data from the CSV owner over the LAN.


To deploy the VSA agent as a proxy, check whether you meet the following requirements:

  • All Hyper-V client nodes in the cluster must run Windows 2012 R2 (or later versions), including nodes with VSA installed and nodes that host VMs on CSV storage but do not have the VSA.
  • Virtual machines must reside on cluster shared volume (CSV) storage that is directly connected to the Hyper-V cluster.

Last modified: 1/22/2019 3:51:11 PM