Holos – QEMU/KVM with a compose-style YAML, GPUs and health checks
I got tired of libvirt XML and Vagrant's Ruby/reload dance for single-host VM stacks, so I built a compose-style runtime directly on QEMU/KVM. What's there: GPU passthrough as a first-class primitive (VFIO, OVMF, per-instance EFI vars), healthchecks that gate depends_on over SSH, socket-multicast L2 between VMs with no root and no bridge config, cloud-init wired through the YAML, Dockerfile support for provisioning. What it's not: Kubernetes. No clustering, no live migration, no control plane. Single host. Prototype, but I'm running it on real hardware. Curious what breaks for…
In plain words
Holos is a QEMU/KVM runtime for managing single-host VM stacks using YAML configuration similar to Docker Compose. It simplifies VM management by eliminating libvirt XML complexity and includes GPU passthrough support, health checks that control service dependencies, inter-VM networking without root privileges, cloud-init integration, and Docker-based provisioning. Designed for developers who need local multi-VM environments rather than clustered infrastructure, it operates as a prototype on individual hardware without clustering, live migration, or orchestration features.
written from the facts on this page · September 2026
From the sources
In the maker’s words, at launch
I got tired of libvirt XML and Vagrant's Ruby/reload dance for single-host VM stacks, so I built a compose-style runtime directly on QEMU/KVM. What's there: GPU passthrough as a first-class primitive (VFIO, OVMF, per-instance EFI vars), healthchecks that gate depends_on over SSH, socket-multicast L2 between VMs with no root and no bridge config, cloud-init wired through the YAML, Dockerfile support for provisioning. What it's not: Kubernetes. No clustering, no live migration, no control plane. Single host. Prototype, but I'm running it on real hardware. Curious what breaks for people.
Does a similar job
all alternatives →- HCHolos – Configure Kubernetes with CUE data structures instead of YAML2024 · holos.run · ▲77
Hi HN! I’m excited to share Holos, a Go command line tool we wrote to fill the configuration management gap in Kubernetes. Holos uses CUE to configure software distributed with Helm and Kustomize using a well defined, type safe language eliminating the need to template YAML. You probably know (or are) someone who has suffered with the complexity of plain text YAML templates and merging multiple values.yaml files together to configure software running in Kubernetes. We built Holos so we don’t have to template YAML but we can still integrate software distributed with Helm and Kustomize…
- LTLightweight tool for managing Linux virtual machinesSep 2025 · github.com · ▲144
hey guys. the other day i was migrating hosting providers and i just needed something not too heavy and convenient to spin up my backups for awhile and realised there is almost nothing out there. kimchi hasn't been updated for years and cockpit is heavy. so here's something i came up with in a couple hours because of a sudden urge, nothing fancy just basic creation with cloud init, lifecycle management and image/storage, but it's modern-ish and it compiles to a 8.4mb binary inclusive of the embedded web UI, CLI and API, and only dep is libvirt.
- WMWe made glhf.chat – run almost any open-source LLM, including 405B2024 · glhf.chat · ▲161
Try it out! https://glhf.chat/ Hey HN! We’ve been working for the past few months on a website to let you easily run (almost) any open-source LLM on autoscaling GPU clusters. It’s free for now while we figure out how to price it, but we expect to be cheaper than most GPU offerings since we can run the models multi-tenant. Unlike Together AI, Fireworks, etc, we’ll run any model that the open-source vLLM project supports: we don’t have a hardcoded list. If you want a specific model or finetune, you don’t have to ask us for it: you can just paste the Hugging Face link in and…
- QCQvm-Create-Windows-Qube: The most secure and private way to run Windows2021 · github.com · ▲120
- SMSub-millisecond VM sandboxes using CoW memory forkingMar 2026 · github.com · ▲311
I wanted to see how fast an isolated code sandbox could start if I never had to boot a fresh VM. So instead of launching a new microVM per execution, I boot Firecracker once with Python and numpy already loaded, then snapshot the full VM state. Every execution after that creates a new KVM VM backed by a `MAP_PRIVATE` mapping of the snapshot memory, so Linux gives me copy-on-write pages automatically. That means each sandbox starts from an already-running Python process inside a real VM, runs the code, and exits. These are real KVM VMs, not containers: separate guest kernel, separate guest…
- HOHigh-order Virtual Machine (HVM) – A Parallel Functional Runtime2022 · github.com · ▲150
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With social media and now AI, its important to keep the indie web alive. There are many people who write frequently. Blogosphere tries to highlight them by fetching the recent posts from personal blogs across many categories. There are two versions: Minimal (HN-inspired, fast, static): https://text.blogosphere.app/ Non-minimal: https://blogosphere.app/ If you don't find your blog (or your favorite ones), please add them. I will review and approve it.
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