Chapter 3. Preparing a virt-who host

Use this procedure to configure a Red Hat Enterprise Linux 7 server to run the virt-who service for VMware vCenter and Microsoft Hyper-V. The server can be physical or virtual.

You do not need a separate virt-who host for Red Hat hypervisors.


  1. Install a Red Hat Enterprise Linux 7 server. Only a CLI environment is required. For more information, see the Red Hat Enterprise Linux 7 Installation Guide.
  2. Register the server:

    # subscription-manager register --auto-attach
  3. Open a network port for communication between virt-who and the subscription service:

    # firewall-cmd --add-port="443/tcp"
    # firewall-cmd --add-port="443/tcp" --permanent
  4. Open a network port for communication between virt-who and each hypervisor or virtualization manager:

    • VMware vCenter: TCP port 443
    • Microsoft Hyper-V: TCP port 5985
  5. Install virt-who:

    # yum install virt-who
  6. Optional: Edit the /etc/virt-who.conf file to change or add global settings. These settings apply to all virt-who connections from this server.

    • Change the value of VIRTWHO_INTERVAL to specify how often, in minutes, virt-who queries the virtualization platform. Because the virtual machines are granted temporary subscriptions for up to seven days, frequent queries are not required; you can select an interval that suits the size of your environment. Once a day (1440) is suitable for most environments.
    • If you want to use an HTTP proxy for virt-who communication, add a line specifying the proxy:

    • If you do not want to use an HTTP proxy for any virt-who communication from this server, add the following line:

  7. Start and enable the virt-who service:

    # systemctl enable --now virt-who