Cloud Hypervisor vs Harvester

Cloud Hypervisor is a free, open-source virtual machine monitor written in Rust for modern cloud workloads. It runs modern Linux and Windows guests on Linux hosts with x86-64 or AArch64 architectures, using minimal hardware emulation. Operators can manage VM lifecycles through a REST API or command-line interface, with an optional D-Bus API. It supports snapshots, nested virtualization, paravirtualized devices, physical device passthrough, and live migration between hosts without interrupting VMs. Migration data can be encrypted using mutual TLS. The maker says direct kernel boot reaches userspace in less than 100 ms. The project is supported by Kata Containers for running secure containerized workloads and is governed openly as part of the Linux Foundation. It has no commercial plan or usage limits stated. Linux hosts need kernel 4.11 or later for required KVM functionality; kernel 5.6 is recommended for adequate performance. Packages for some popular Linux distributions are available through the Open Build Service. For help, the project points users to GitHub discussions or Slack, with GitHub issues for bug reports and a mailing list for broader discussion.

Harvester is free, open-source hyperconverged infrastructure for bare-metal servers, combining virtualization and distributed storage. It is intended for VMs, Kubernetes running in VMs, containerized workloads on bare metal, and edge workloads. Its architecture uses Kubernetes, KubeVirt, Longhorn, Grafana, Prometheus, and SUSE Linux Micro. Users can create, edit, clone, and delete VMs, with SSH key injection, cloud-init, and graphical or serial consoles. Live migration moves a VM to another host without downtime, but requires matching physical CPU specifications. Storage includes distributed block storage and tiering; VM backups use NFS or S3-compatible targets and are limited to Longhorn volumes. Harvester installs directly on bare metal from a bootable ISO; new installations starting with v1.8 require UEFI boot. Three nodes are needed for multi-node features and high availability, while production recommendations call for at least 16 CPU cores, 64 GB memory, 500 GB disk, and 10 Gbps Ethernet. Laptops and nested virtualization are unsupported.