3.3. Installing Guest Agents and Drivers

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3.3.1. Red Hat Virtualization Guest Agents, Tools, and Drivers

The Red Hat Virtualization guest agents, tools, and drivers provide additional functionality for virtual machines, such as gracefully shutting down or rebooting virtual machines from the VM Portal and Administration Portal. The tools and agents also provide information for virtual machines, including:

  • Resource usage
  • IP addresses
  • Installed applications

The guest agents, tools and drivers are distributed as an ISO file that you can attach to virtual machines. This ISO file is packaged as an RPM file that you can install and upgrade from the Manager machine.

You need to install the guest agents and drivers on a virtual machine to enable this functionality for that machine.

Table 3.1. Red Hat Virtualization Guest Drivers
DriverDescriptionWorks on


Paravirtualized network driver provides enhanced performance over emulated devices like rtl.

Server and Desktop.


Paravirtualized HDD driver offers increased I/O performance over emulated devices like IDE by optimizing the coordination and communication between the virtual machine and the hypervisor. The driver complements the software implementation of the virtio-device used by the host to play the role of a hardware device.

Server and Desktop.


Paravirtualized iSCSI HDD driver offers similar functionality to the virtio-block device, with some additional enhancements. In particular, this driver supports adding hundreds of devices, and names devices using the standard SCSI device naming scheme.

Server and Desktop.


Virtio-serial provides support for multiple serial ports. The improved performance is used for fast communication between the virtual machine and the host that avoids network complications. This fast communication is required for the guest agents and for other features such as clipboard copy-paste between the virtual machine and the host and logging.

Server and Desktop.


Virtio-balloon is used to control the amount of memory a virtual machine actually accesses. It offers improved memory overcommitment.

Server and Desktop.


A paravirtualized display driver reduces CPU usage on the host and provides better performance through reduced network bandwidth on most workloads.

Server and Desktop.

Table 3.2. Red Hat Virtualization Guest Agents and Tools
Guest agent/toolDescriptionWorks on


Enables the Red Hat Virtualization Manager to receive internal virtual machine events and information such as IP address and installed applications. Also enables the Manager to execute specific commands on a virtual machine, such as shut down or reboot.

On virtual machines running Red Hat Enterprise Linux 6 or 7, ovirt-guest-agent-common installs tuned on your virtual machine and configures it to use an optimized, virtual machine profile. Use qemu-guest-agent on Red Hat Enterprise Linux 8 virtual machines

Server and Desktop.


Used instead of ovirt-guest-agent-common on Red Hat Enterprise Linux 8 virtual machines. It is installed and enabled by default.

Server and Desktop.


The SPICE agent supports multiple monitors and is responsible for client-mouse-mode support to provide a better user experience and improved responsiveness than the QEMU emulation. Cursor capture is not needed in client-mouse-mode. The SPICE agent reduces bandwidth usage when used over a wide area network by reducing the display level, including color depth, disabling wallpaper, font smoothing, and animation. The SPICE agent enables clipboard support allowing cut and paste operations for both text and images between client and virtual machine, and automatic guest display setting according to client-side settings. On Windows-based virtual machines, the SPICE agent consists of vdservice and vdagent.

Server and Desktop.


An agent that enables users to automatically log in to their virtual machines based on the credentials used to access the Red Hat Virtualization Manager.


3.3.2. Installing the Guest Agents, Tools, and Drivers on Windows

To install the guest agents, tools, and drivers on a Windows virtual machine:

  1. On the Manager machine, install the rhv-guest-tools-iso package:

    yum install rhv-guest-tools-iso*

    After you install the package, the ISO file is located in /usr/share/rhv-guest-tools-iso/RHV-toolsSetup_version.iso on the Manager machine.

  2. Upload RHV-toolsSetup_version.iso to a data storage domain. See Uploading Images to a Data Storage Domain in the Administration Guide for details.
  3. In the Administration or VM Portal, if the virtual machine is running, use the Change CD button to attach the RHV-toolsSetup_version.iso file to each of your virtual machines. If the virtual machine is powered off, click the Run Once button and attach the ISO as a CD.


    If you install the guest agents and drivers from the command line or as part of a deployment tool such as Windows Deployment Services, you can append the options ISSILENTMODE and ISNOREBOOT to RHEV-toolsSetup.exe to silently install the guest agents and drivers and prevent the machine on which they are installed from rebooting immediately after installation. You can reboot the machine later, after the deployment process is complete.

  4. Log in to the virtual machine.
  5. Select the CD Drive containing the RHV-toolsSetup_version.iso file.
  6. Double-click RHEV-toolsSetup.exe.
  7. Click Next at the welcome screen.
  8. Follow the prompts on the RHEV-Tools InstallShield Wizard window. Ensure all check boxes in the list of components are selected.
  9. Once installation is complete, select Yes, I want to restart my computer now and click Finish to apply the changes.

The guest agents and drivers now pass usage information to the Red Hat Virtualization Manager and allow you to access USB devices, single sign-on into virtual machines, and other functionality. The Red Hat Virtualization guest agent runs as a service called RHEV Agent that you can configure using the rhev-agent configuration file located in C:\Program Files\Redhat\RHEV\Drivers\Agent.

For information on updating the guest agents and drivers, see Section 6.6.2, “Updating the Guest Agents and Drivers on Windows”

3.3.3. Automating Guest Additions on Windows Guests with Red Hat Virtualization Application Provisioning Tool(APT)

Red Hat Virtualization Application Provisioning Tool (APT) is a Windows service that can be installed on Windows virtual machines and templates. When the APT service is installed and running on a virtual machine, attached ISO files are automatically scanned. When the service recognizes a valid Red Hat Virtualization guest tools ISO, and no other guest tools are installed, the APT service installs the guest tools. If guest tools are already installed, and the ISO image contains newer versions of the tools, the service performs an automatic upgrade. This procedure assumes you have attached the rhev-tools-setup.iso ISO file to the virtual machine.

Installing the APT Service on Windows

  1. Log in to the virtual machine.
  2. Select the CD Drive containing the RHV-toolsSetup_version.iso file.
  3. Double-click RHEV-Application Provisioning Tool.
  4. Click Yes in the User Account Control window.
  5. Once installation is complete, ensure the Start RHEV-apt Service check box is selected in the RHEV-Application Provisioning Tool InstallShield Wizard window, and click Finish to apply the changes.

Once the APT service has successfully installed or upgraded the guest tools on a virtual machine, the virtual machine is automatically rebooted. This happens without confirmation from the user logged in to the machine. The APT Service will also perform these operations when a virtual machine created from a template that has the APT Service already installed is booted for the first time.


The RHEV-apt service can be stopped immediately after install by clearing the Start RHEV-apt Service check box. You can stop, start, or restart the service at any time using the Services window.

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