System Requirements for Virtual Server Agent with Microsoft Azure Stack Hub

Azure Stack Hub Version

Commvault software is supported with Microsoft Azure Stack Hub version 2002 and more recent versions.


To protect Azure Stack Hub virtual machines, you must upgrade your CommCell environment to Commvault version 11.20 or a more recent release, and you must upgrade all of your Azure Stack Hub virtual machines to Azure Stack Hub 2002 or a more recent release. Using previous versions of Azure Stack Hub with previous versions of the Commvault software is possible. However, with those previous versions, a known Microsoft issue with snapshots of unmanaged VMs can cause data corruption. To avoid data corruption, you must upgrade both your CommCell environment and your Azure Stack Hub environment.

Virtual Server Agent Proxy Requirements

A physical machine or an Azure Stack Hub virtual machine with the Virtual Server Agent (VSA) installed can act as a VSA proxy to perform backups and restores.

For best results, deploy the VSA proxy and MediaAgent on virtual machines in the Azure Stack Hub cloud.

If you have existing VSA proxies that are used to support Azure Classic or Azure Resource Manager, use different proxies for Azure Stack Hub.

Deploying the VSA proxy on an Azure Stack Hub VM that is compute optimized will support faster backups.

A VSA proxy must meet the following requirements:

  • The VSA proxy machine must run one of the following operating systems:

    • Windows Server 2019

    • Windows Server 2016

    • Windows Server 2012 R2

  • Minimum of 100 GB disk space.

  • Minimum of 4 GB RAM, beyond the requirements of the operating system and any other running applications. See Sizes for virtual machines in Azure Stack Hub for more information.

  • Install Azure PowerShell and download Azure Stack Hub tools as described in Install PowerShell for Azure Stack Hub.

  • A VSA proxy deployed on a virtual machine in Azure Stack Hub must have a public IP address.

Guest Operating Systems

Virtual machines being backed up can have any of the guest operating systems that are supported by the Azure Stack Hub platform.

Firewall Requirements

If you deploy a CommServe host in an environment with firewalls, create a persistent route from the CommServe host to the VSA proxy, as documented in Setting Up Network Gateway Connections Using a Predefined Network Topology. Specify the RESTRICTED setting for connections from the CommServe host to the VSA proxy (step 3 under If you chose not to use predefined network topologies) and the BLOCKED setting in the CommServe node settings for the proxy (step 9).

If a firewall proxy is installed, configure Internet options for the firewall proxy machine. On the HTTP Proxy tab of the Internet Options dialog box, enter the user name and password for the firewall proxy machine, using only the user name and not including the domain name with the user name.


When a firewall proxy is configured, you must add the Azure Stack Hub resource manager URL to the whitelist.

If multiple proxies are deployed in the Azure Stack Hub cloud, a two-way firewall configuration needs to be set up to enable proxies to communicate with each other. This can be achieved by creating two client groups, adding all Azure Stack Hub VSA proxies under both client groups, and creating a two-way network topology that includes the two client groups.

Hardware Specifications

For information about hardware requirements for the Virtual Server Agent, see Hardware Specifications for Virtual Server Agent.


Certain third-party software and service releases (together, “Releases”) may not be supported by Commvault. You are solely responsible for ensuring Commvault’s products and services are compatible with any such Releases.