Harvester — Open-Source Hyperconverged Infrastructure for Kubernetes

Introduction

Harvester is an open-source hyperconverged infrastructure (HCI) solution built on Kubernetes, developed by SUSE (formerly Rancher Labs). It provides an integrated platform for running virtual machines alongside containers on bare-metal servers, eliminating the need for separate hypervisor and storage infrastructure.

What Harvester Does

• Runs virtual machines on bare metal using KubeVirt as the virtualization layer
• Provides distributed block storage through an integrated Longhorn storage backend
• Manages VM lifecycle including live migration, snapshots, and backup/restore
• Supports multi-cluster management when integrated with Rancher
• Offers a web-based dashboard for VM, network, and storage administration

Architecture Overview

Harvester ships as a bootable ISO that installs a minimal Linux OS with an embedded RKE2 Kubernetes cluster. KubeVirt handles VM scheduling and execution using KVM/QEMU. Longhorn provides replicated distributed storage across cluster nodes. Multus CNI enables advanced networking with VLAN support. All components are managed through Kubernetes custom resources, making the entire stack declarative and API-driven.

Self-Hosting & Configuration

• Boot the Harvester ISO on bare-metal servers with at least 8 CPU cores and 32 GB RAM
• Configure networking during installation with management and VLAN interfaces
• Add nodes to form a high-availability cluster (minimum 3 nodes recommended)
• Import into Rancher for centralized multi-cluster management and RBAC
• Upload VM images (ISO, qcow2, raw) through the dashboard or API for VM provisioning

Key Features

• Unified platform for VMs and containers without separate hypervisor infrastructure
• Live migration of VMs between nodes for zero-downtime maintenance
• VM backup and restore with S3-compatible storage targets
• Terraform provider for infrastructure-as-code VM provisioning
• Nested virtualization support for running Kubernetes clusters inside Harvester VMs

Comparison with Similar Tools

• VMware vSphere — Enterprise-grade with deeper ecosystem; Harvester is free and Kubernetes-native
• Proxmox VE — Mature KVM/LXC platform; Harvester integrates natively with the Kubernetes ecosystem
• OpenStack — Full IaaS with more services; Harvester is simpler to deploy and manage
• Nutanix — Commercial HCI leader; Harvester offers similar HCI capabilities as open source
• KubeVirt standalone — VM operator only; Harvester bundles storage, networking, and management UI

FAQ

Q: Can Harvester replace VMware? A: For many use cases, yes. Harvester handles VM lifecycle, live migration, HA, and storage. Complex VMware features like DRS and vSAN deduplication are not yet matched.

Q: What are the minimum hardware requirements? A: A single node needs 8 CPU cores, 32 GB RAM, and 250 GB disk. Production clusters should have 3+ nodes.

Q: Does it support GPU passthrough? A: Yes. PCIe passthrough is supported for GPU and other devices, enabling GPU workloads in VMs.

Q: How does it integrate with Rancher? A: Harvester registers as a node driver in Rancher, enabling centralized VM and cluster management through the Rancher dashboard.

Sources

• https://github.com/harvester/harvester
• https://harvesterhci.io/