Migrating from Proxmox to Incus: The Ultra-Lightweight, Kernel-Level Solution for Container Management
Introduction: The Changing Landscape of Enterprise Virtualization
For years, Proxmox Virtual Environment (PVE) has been a dominant force in the open-source virtualization market. By combining Kernel-based Virtual Machines (KVM) with Linux Containers (LXC), Proxmox delivered a robust, web-managed ecosystem that served as an excellent alternative to costly proprietary hypervisors. However, as infrastructure demands shift toward edge computing, microservices, and maximum hardware efficiency, the traditional hypervisor model is facing scrutiny.
Enter Incus—the powerful, community-driven fork of LXD created under the Linux Containers project umbrella. Incus represents a paradigm shift by focusing primarily on system containers and lightweight virtual machines. For organizations looking to eliminate hypervisor overhead, streamline orchestration, and achieve near-bare-metal performance, replacing Proxmox with Incus is becoming a highly strategic move. This comprehensive guide explores why and how to transition to this ultra-lightweight, kernel-level management system.
Understanding Incus: The Evolution of System Containers
To understand the value of Incus, one must first understand the distinction between application containers (like Docker) and system containers (LXC/LXD). While Docker packages a single process or application, system containers act as full, lightweight Linux operating systems. They run an init system (like systemd), support SSH, and behave exactly like a virtual machine, but without the massive hardware emulation layer.
Incus acts as a modern, secure, and highly scalable daemon to manage these containers. Born out of the necessity to keep the LXD ecosystem truly open-source and community-driven, Incus offers a clean, production-ready API, an intuitive command-line interface, and robust clustering capabilities right out of the box.
Why Move Away from Proxmox?
While Proxmox is an exceptional tool, it carries inherent design characteristics that may not align with streamlined, modern infrastructure needs:
- Heavy Footprint: Proxmox relies heavily on KVM for full virtualization. Even when idle, KVM instances consume fixed blocks of RAM and introduce CPU virtualization overhead.
- Monolithic Web UI: The Proxmox interface is tightly coupled with its clustering and storage mechanisms. While convenient for GUI-driven administrators, it can be cumbersome for DevOps workflows driven by GitOps and infrastructure-as-code (IaC).
- Debian Core Overhead: Proxmox effectively turns a standard Debian installation into a heavy-duty appliance, limiting customization options for minimalist deployments.
The Incus Advantage: Ultra-Lightweight Kernel-Level Efficiency
Replacing Proxmox with Incus introduces a wave of operational and architectural advantages centered around efficiency and simplicity.
1. Near-Zero Performance Overhead
Because Incus relies on native kernel features such as namespaces, cgroups, and seccomp profiles, containers share the host kernel. There is no hypervisor layer translating instructions. A system container managed by Incus achieves up to 99% of bare-metal performance, allowing for significantly higher density—running up to tens or hundreds of containers on hardware where Proxmox could only host a dozen heavy KVMs.
2. Dynamic Resource Allocation
In Proxmox, modifying a VM's RAM or CPU allocation often requires a reboot or complex hot-plugging configurations. Incus handles resource constraints dynamically. Need to limit a container to 4GB of RAM or 2 CPU cores? A single CLI command applies the restriction instantly, at the kernel level, without disrupting the running system.
Incus redefines infrastructure agility by treating system resources as fluid assets that can be throttled, expanded, and reassigned on the fly without a single microsecond of downtime.
3. Modern REST API and Developer-First Design
Unlike Proxmox's traditional management style, Incus is built from the ground up with a powerful REST API. It integrates flawlessly with modern automation tools like OpenTofu, Terraform, and Ansible. This makes it an ideal fit for cloud-native pipelines, allowing systems administrators to manage bare-metal infrastructure using the same declarative workflows they use for AWS or Google Cloud.
Feature Comparison: Proxmox vs. Incus
When evaluating a migration, it is critical to compare how key operational features map between the two platforms:
| Feature | Proxmox VE | Incus |
|---|---|---|
| Primary Virtualization | KVM (Heavyweight) & LXC | LXC (System Containers) & QEMU (Lightweight VMs) |
| Resource Consumption | Moderate to High | Ultra-Low / Near Bare-Metal |
| Clustering | Corosync / PVE Cluster (Max ~32 nodes optimally) | Built-in dqlite (Scales cleanly to dozens of nodes) |
| Storage Backends | ZFS, Ceph, LVM, NFS | ZFS, Btrfs, Ceph, LVM, Directory |
| Management | Web-first UI, API available | CLI-first, powerful REST API, Open-source Web UIs |
Architecting the Migration: From Proxmox to Incus
Transitioning from a Proxmox environment to Incus requires a structured approach, particularly when converting existing workloads.
Step 1: Preparing the Incus Host
Incus can be installed on almost any modern Linux distribution, though Ubuntu, Debian, and Rocky Linux are common choices. Unlike Proxmox, which dictates the entire OS installation, Incus installs cleanly as a package, leaving your underlying operating system unbloated. Running incus admin init walks you through setting up storage pools (such as ZFS or Btrfs) and network bridges.
Step 2: Migrating LXC Containers
Because Proxmox uses standard LXC underneath its GUI, migrating these containers to Incus is highly efficient. The process generally involves:
- Backing up or exporting the container rootfs from Proxmox as a tarball.
- Transferring the archive to the Incus host.
- Using the
incus image importcommand to ingest the rootfs. - Launching a new Incus container from that imported image.
Step 3: Migrating KVM VMs to Incus Virtual Machines
While Incus is celebrated for its system containers, it also manages full virtual machines via QEMU when strict kernel isolation is required (e.g., for running Windows or non-native kernels). To migrate a Proxmox KVM VM to an Incus VM, administrators can use the incus-migrate tool, an automated utility that safely converts raw or qcow2 disk images into Incus-compatible virtual instances.
Conclusion: Is Incus Right for Your Enterprise?
Replacing Proxmox with Incus is not merely a change in tooling; it is an architectural decision to embrace efficiency, simplicity, and modern DevOps practices. If your organization relies heavily on Linux-based workloads and requires maximum hardware density, lightning-fast deployment times, and native API orchestration, Incus is an unparalleled solution. By shedding the hypervisor tax and leveraging kernel-level virtualization, Incus delivers a lean, high-performance infrastructure ready for the future of enterprise computing.