Types of libvirt Driver Daemons

Oracle Linux 9 provides functionality for two different types of libvirt driver daemons: Modular and Monolithic. The granularity in which you can configure individual virtualization drivers depends on which libvirt daemon you use. For example:

  • Modular libvirt - Oracle Linux 9 Fresh Install

    Modular libvirt, which is newly introduced in Oracle Linux 9, provides a specific daemon for each hypervisor driver. These include:

    • virtqemud: is the QEMU management daemon, for running virtual machines on KVM.
    • virtnetworkd: is the virtual network management daemon.
    • virtnodedevd: is the host physical device management daemon.
    • virtnwfilterd: is the host firewall management daemon.
    • virtsecretd: is the host secret management daemon.
    • virtstoraged: is the host storage management daemon.
    • virtinterfaced: is the host Network Interface Card (NIC) management daemon.
    • virtproxyd is a virtualization proxy daemon that lets remote clients to securely access the libvirt APIs.

    The name of the daemon reflects the name of the host driver, for example: virt [DRIVER]d. Each driver daemon has a separate configuration file that resides in libvirt directory. For example, the configuration file path for QEMU management driver daemon is /etc/libvirt/virtqemud.conf.

    Modular driver daemons provide better options for fine-tuning and managing the libvirt system resources. When you perform a fresh install of Oracle Linux 9, the libvirt modular virtualization driver daemons are configured by default.

    Note:

    When the virt$[DRIVER]d daemon is managed by systemd other features are also available, most notably socket activation. For more information about the use of modular sockets and systemd integration, see https://libvirt.org/daemons.html#modular-sockets.

  • Monolithic libvirt - Update to Oracle Linux 9

    By default, the traditional monolithic daemon, known as libvirtd is configured when you update from Oracle Linux 8 to Oracle Linux 9. The libvirtd daemon controls a wide variety of virtualization drivers by using a single configuration file (/etc/libvirt/libvirtd.conf). In some instances, system resources might be used inefficiently when using the libvirtd centralized configuration. Therefore, we recommend that Oracle Linux 9 users switch to the modular libvirt driver daemons. For instructions, see https://libvirt.org/daemons.html#switching-to-modular-daemons.

For general information about the usage of libvirt daemons, see https://libvirt.org/daemons.html.