LXD vs virt-manager

LXD is an open-source platform for managing system containers and virtual machines on Linux. It brings LXC-based containers and KVM-based virtual machines together, with images for many Linux distributions and Windows virtual machines. Management options include a command line, REST API, web UI and third-party tools; the same HTTP API supports local and remote access. An official web UI is available by default starting with LXD 5.21.0 LTS. Features include resource limits, scheduled and expiring snapshots, projects, hardware passthrough, live migration and advanced networking. Containers run unprivileged by default, and virtual machines support UEFI Secure Boot and vTPM. LXD can run from a laptop to a data-center deployment; documentation describes clusters of up to 50 servers with thousands of instances. LXD is free, with the open-source plan listed at free. Ubuntu Pro Personal is also free for up to five physical Ubuntu systems. Enterprise workstation and server subscriptions are $25 a year and $500 a year, respectively.

virt-manager is a desktop interface for managing virtual machines through libvirt, chiefly for KVM, with support for Xen and LXC as well. It connects to local and remote hosts and displays live performance and resource-use statistics for running domains. Setup wizards help create domains and assign resources and virtual hardware, while an embedded VNC and SPICE viewer provides a graphical guest console. The interface also manages host virtual networks, storage pools, and network interfaces. Companion command-line tools handle provisioning, cloning, and editing virtual machines. virt-manager runs on Linux and OpenBSD hosts, supports both guest architectures, and includes snapshots and GPU acceleration. Installation options listed include Fedora, Debian, Gentoo, and OpenBSD packages, plus a source release. It is distributed under the GNU General Public License; current releases are GPG signed, with verification instructions. Documentation and a FAQ are available, support questions go to GitHub Discussions, and bug tracking is on GitHub.