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Install the QEMU guest agent

Enable advanced features like quiesced snapshots and improved monitoring by installing the QEMU guest agent on your virtual machines (VMs). The QEMU guest agent is a daemon that runs on the VM and passes information to the host about the VM, users, file systems, and secondary networks.

You must install the QEMU guest agent on VMs created from operating system images that are not provided by Red Hat.

Installing the QEMU guest agent on a Linux VM

The qemu-guest-agent is available by default in Fedora virtual machines (VMs). To create snapshots of a VM in the Running state with the highest integrity, install the QEMU guest agent.

The QEMU guest agent takes a consistent snapshot by attempting to quiesce the VM file system. 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 a snapshot is taken are reflected in the snapshot indications that are displayed in the web console or CLI. If these conditions do not meet your requirements, try creating the snapshot again, or use an offline snapshot

Prerequisites

  • You have installed the OpenShift CLI (oc).

Procedure

  1. Log in to the VM by using a console or SSH.

  2. Install the QEMU guest agent by running the following command:

    $ yum install -y qemu-guest-agent

  3. Ensure the service is persistent and start it:

    $ systemctl enable --now qemu-guest-agent
Verification

  • Run the following command to verify that AgentConnected is listed in the VM spec:

    $ oc get vm <vm_name>

Installing the QEMU guest agent on a Windows VM

For Windows virtual machines (VMs), the QEMU guest agent is included in the VirtIO drivers. You can install the drivers during a Windows installation or on an existing Windows VM.

To create snapshots of a VM in the Running state with the highest integrity, install the QEMU guest agent.

The QEMU guest agent takes a consistent snapshot by attempting to quiesce the VM file system. 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.

Note that in a Windows guest operating system, quiescing also requires the Volume Shadow Copy Service (VSS). Therefore, before you create a snapshot, ensure that VSS is enabled on the VM as well.

The conditions under which a snapshot is taken are reflected in the snapshot indications that are displayed in the web console or CLI. If these conditions do not meet your requirements, try creating the snapshot again or use an offline snapshot.

Procedure

  1. In the Windows guest operating system, use the File Explorer to navigate to the guest-agent directory in the virtio-win CD drive.

  2. Run the qemu-ga-x86_64.msi installer.

Verification

  1. Obtain a list of network services by running the following command:

    $ net start

  2. Verify that the output contains the QEMU Guest Agent.