Incus — Powerful System Container and Virtual Machine Manager

Introduction

Incus is a community-maintained fork of Canonical's LXD, managed under the Linux Containers project. It provides full system containers and virtual machines through a single tool, combining the density of containers with the isolation of VMs under one consistent API.

What Incus Does

• Manages both system containers (LXC) and QEMU-based virtual machines
• Provides image-based workflows with a public image server
• Supports clustering for distributing instances across multiple hosts
• Enables live migration of running containers and VMs
• Offers fine-grained resource limits for CPU, memory, disk, and network

Architecture Overview

Incus runs as a daemon exposing a REST API. The CLI (incus) communicates with this API to manage instances. Containers use LXC with kernel namespaces and cgroups. VMs use QEMU/KVM with virtio devices. Both instance types share the same storage, network, and profile abstractions, allowing unified management.

Self-Hosting & Configuration

• Install from distro packages (Zabbly repo for Debian/Ubuntu) or build from Go source
• Run incus admin init to configure storage pool, network bridge, and clustering
• Use profiles to define reusable configurations for CPU, memory, and devices
• Configure storage backends: ZFS, Btrfs, LVM, or directory
• Set up clustering by joining additional nodes to the leader

Key Features

• Unified management of containers and VMs through one tool
• Built-in image server with pre-built images for 30+ Linux distributions
• Clustering with automatic instance placement and failure recovery
• Snapshot and backup support with scheduled automatic snapshots
• Project-based multi-tenancy for isolating workloads and users

Comparison with Similar Tools

• LXD — Incus is the community fork after Canonical moved LXD to a CLA model; feature-equivalent with independent governance
• Docker — application containers; Incus provides full system containers with init, SSH, and multi-process support
• Proxmox VE — hypervisor with web UI; Incus is CLI/API-first and lighter weight
• libvirt/virsh — lower-level VM management; Incus adds container support and a modern REST API

FAQ

Q: What is the difference between Incus and LXD? A: Incus is a community fork of LXD maintained by the Linux Containers project. It diverged after Canonical changed LXD's licensing. Functionally they are similar, with Incus adding community-driven features.

Q: Can I migrate from LXD to Incus? A: Yes. The Incus project provides a lxd-to-incus migration tool that converts LXD installations in place.

Q: Does Incus replace Docker? A: They serve different purposes. Docker runs application containers (one process). Incus runs system containers (full OS) and VMs. They can complement each other.

Q: What storage backends are supported? A: ZFS, Btrfs, LVM, Ceph, and plain directory. ZFS and Btrfs offer the best snapshot and copy-on-write performance.

Sources

• https://github.com/lxc/incus
• https://linuxcontainers.org/incus/