System Requirements for Virtual Server Agent with Microsoft Azure Stack

Azure Stack Version

Commvault software is supported with Microsoft Azure Stack version 1901.


To protect your Azure Stack 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 virtual machines to Azure Stack Hub 2002 or a (more recent release). Using previous versions of Azure Stack 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 environment.

Virtual Server Agent Proxy Requirements

A physical machine or an Azure Stack 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 cloud.

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

Deploying the VSA proxy on an Azure Stack 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 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 for more information.

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

  • A VSA proxy deployed on a virtual machine in Azure Stack 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 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 resource manager URL to the whitelist.

If multiple proxies are deployed in the Azure Stack 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 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.


Third-party maintenance (minor) releases or service packs that are supported by the Commvault software may not be listed in our System Requirements. When possible, Commvault provides information on any known issues related to these minor releases or service packs. In some cases, these minor releases or service packs affect how the Commvault software works. Commvault software may experience changes in functionality as the result of the third-party minor release or service pack. These changes are beyond the control of Commvault. Platforms that are supported in the current version of Commvault software may not be supported in earlier versions of the software. Contact your software provider to ensure that third-party minor releases or service packs are compatible with the Commvault software. Additional considerations regarding minimum requirements and End-of-Life policies from third-party vendors also apply.