Installing the QEMU guest agent on virtual machines

The QEMU guest agent is a daemon that runs on the virtual machine and passes information to the host about the virtual machine, users, file systems, and secondary networks.

Installing QEMU guest agent on a Linux virtual machine

The qemu-guest-agent is widely available and available by default in Red Hat virtual machines. Install the agent and start the service.

To check if your virtual machine (VM) has the QEMU guest agent installed and running, verify that AgentConnected is listed in the VM spec.

To create snapshots of an online (Running state) VM with the highest integrity, install the QEMU guest agent.

The QEMU guest agent takes a consistent snapshot by attempting to quiesce the VM’s file system as much as possible, depending on the system workload. This ensures that in-flight I/O is written to the disk before the snapshot is taken. If the guest agent is not present, quiescing is not possible and a best-effort snapshot is taken. The conditions under which the snapshot was taken are reflected in the snapshot indications that are displayed in the web console or CLI.

Procedure

  1. Access the virtual machine command line through one of the consoles or by SSH.

  2. Install the QEMU guest agent on the virtual machine:

    1. $ yum install -y qemu-guest-agent

  3. Ensure the service is persistent and start it:

    1. $ systemctl enable --now qemu-guest-agent

You can also install and start the QEMU guest agent by using the custom script field in the cloud-init section of the wizard when creating either virtual machines or virtual machines templates in the web console.

Installing QEMU guest agent on a Windows virtual machine

For Windows virtual machines, the QEMU guest agent is included in the VirtIO drivers. Install the drivers on an existng or new Windows system.

To check if your virtual machine (VM) has the QEMU guest agent installed and running, verify that AgentConnected is listed in the VM spec.

To create snapshots of an online (Running state) VM with the highest integrity, install the QEMU guest agent.

The QEMU guest agent takes a consistent snapshot by attempting to quiesce the VM’s file system as much as possible, depending on the system workload. This ensures that in-flight I/O is written to the disk before the snapshot is taken. If the guest agent is not present, quiescing is not possible and a best-effort snapshot is taken. The conditions under which the snapshot was taken are reflected in the snapshot indications that are displayed in the web console or CLI.

Installing VirtIO drivers on an existing Windows virtual machine

Install the VirtIO drivers from the attached SATA CD drive to an existing Windows virtual machine.

This procedure uses a generic approach to adding drivers to Windows. The process might differ slightly between versions of Windows. See the installation documentation for your version of Windows for specific installation steps.

Procedure

  1. Start the virtual machine and connect to a graphical console.

  2. Log in to a Windows user session.

  3. Open Device Manager and expand Other devices to list any Unknown device.

    1. Open the Device Properties to identify the unknown device. Right-click the device and select Properties.

    2. Click the Details tab and select Hardware Ids in the Property list.

    3. Compare the Value for the Hardware Ids with the supported VirtIO drivers.

  4. Right-click the device and select Update Driver Software.

  5. Click Browse my computer for driver software and browse to the attached SATA CD drive, where the VirtIO drivers are located. The drivers are arranged hierarchically according to their driver type, operating system, and CPU architecture.

  6. Click Next to install the driver.

  7. Repeat this process for all the necessary VirtIO drivers.

  8. After the driver installs, click Close to close the window.

  9. Reboot the virtual machine to complete the driver installation.

Installing VirtIO drivers during Windows installation

Install the VirtIO drivers from the attached SATA CD driver during Windows installation.

This procedure uses a generic approach to the Windows installation and the installation method might differ between versions of Windows. See the documentation for the version of Windows that you are installing.

Procedure

  1. Start the virtual machine and connect to a graphical console.

  2. Begin the Windows installation process.

  3. Select the Advanced installation.

  4. The storage destination will not be recognized until the driver is loaded. Click Load driver.

  5. The drivers are attached as a SATA CD drive. Click OK and browse the CD drive for the storage driver to load. The drivers are arranged hierarchically according to their driver type, operating system, and CPU architecture.

  6. Repeat the previous two steps for all required drivers.

  7. Complete the Windows installation.