/etc/libvirt — Libvirt Configuration Directory

The /etc/libvirt directory holds system-wide configuration files for the libvirt daemon (libvirtd) and associated virtualization drivers (like QEMU/KVM, LXC, Xen, etc.). These configs define how virtualization services behave, how domains are defined, and how networking/storage pools are managed.

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Key Subdirectories and Files

1. /etc/libvirt/qemu/

• Contains XML configs for persistent QEMU/KVM virtual machines.

• Files:

  • *.xml → One XML file per VM.

  • autostart/ → Symbolic links for VMs that autostart at boot.

/etc/libvirt/qemu/ubuntu-vm.xml
/etc/libvirt/qemu/autostart/ubuntu-vm.xml

2. /etc/libvirt/qemu/networks/

• Stores virtual network definitions.

• Files:

  • default.xml → Default NAT network.

  • autostart/ → Symlinks for networks that should autostart.

/etc/libvirt/qemu/networks/default.xml
/etc/libvirt/qemu/networks/autostart/default.xml

3. /etc/libvirt/storage/

• Persistent storage pool definitions.

• Used by virsh pool-* and virsh vol-* commands.

4. /etc/libvirt/libvirtd.conf

• Main configuration file for the libvirtd daemon (deprecated in libvirt >=9.0.0, replaced by virtproxyd).

• Controls:

  • Listening interfaces (unix, tcp, tls)

  • Authentication mechanisms

  • Logging and group permissions

5. /etc/libvirt/libvirt.conf

• User-specific settings for libvirt clients like virsh.

• Affects remote connections and auth behavior (e.g., qemu+ssh).

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Autostart Mechanism

When a domain, network, or storage pool is marked to autostart, libvirt creates a symlink in the respective autostart/ directory:

/etc/libvirt/qemu/autostart/vm-name.xml -> ../vm-name.xml

You can manage autostart via:

virsh autostart vm-name
virsh net-autostart default

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Security Contexts

If SELinux or AppArmor is enabled, libvirt uses security labels defined here:

• /etc/libvirt/qemu.conf: SELinux/AppArmor settings for QEMU/KVM

• Example: Enable dynamic labels (dynamic_ownership = 1)

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Backup and Version Control

To back up all persistent VMs, virtual networks, and storage definitions:

cp -r /etc/libvirt /backup/libvirt-$(date +%F)

To track changes over time:

git init /etc/libvirt
git commit -am "Initial libvirt configs"

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Summary

Path	Purpose
/etc/libvirt/qemu/*.xml	Persistent VM definitions
/etc/libvirt/qemu/networks/*.xml	Virtual network definitions
/etc/libvirt/storage/*.xml	Storage pool definitions
/etc/libvirt/libvirtd.conf	Daemon settings (deprecated for newer)
/etc/libvirt/libvirt.conf	Client-side settings
*/autostart/	Symlinks for auto-started resources

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Let me know if you want visuals, config examples, or comparisons with /var/lib/libvirt and other runtime paths.