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Cozystack
Apache-2.0Cozystack turns bare-metal servers into an open-source private cloud, replacing VMware and public clouds with KubeVirt VMs and managed Kubernetes.
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Overview
VMware Cloud Foundation locks enterprise virtualization behind per-core subscriptions and proprietary hypervisor licensing. Cozystack turns commodity bare-metal servers into an API-driven private cloud where virtual machines, managed Kubernetes clusters, and storage remain entirely under your control. By orchestrating cloud-native projects on Talos Linux, it eliminates commercial license audits without sacrificing infrastructure automation.
Why Cozystack instead of VMware
Instead of proprietary ESXi, vCenter, and vSAN, Cozystack builds a private cloud on Kubernetes primitives. KubeVirt runs virtual machines alongside containers, Cilium and Kube-OVN manage tenant networking, and LINSTOR coordinates replicated block storage on NVMe drives with DRBD. Because components run directly on your hardware, data residency and access policies remain internal, without telemetry phone-home routines or core-count license keys.
Adopting Cozystack replaces graphical consoles and packaged OVA imports with declarative Kubernetes manifests and GitOps workflows. Migrating virtual disks requires converting VMDK files to raw or qcow2 formats for KubeVirt rather than running automated vMotion transfers. In exchange, platform teams gain data sovereignty, predictable hardware economics, and the ability to provision isolated tenant clusters alongside virtual machines from one API.
What it does well
- Unified compute fabric: runs containerized workloads, tenant Kubernetes clusters via Kamaji, and KubeVirt virtual machines under standard Custom Resource Definitions within shared GitOps workflows.
- Locality-aware storage: pairs LINSTOR and DRBD with a scheduler extender that places database pods and virtual machines directly on nodes hosting primary storage replicas.
- Declarative bare-metal OS: boots nodes onto Talos Linux, an immutable operating system without interactive shells, preventing configuration drift across server fleets.
- Tenant network isolation: enforces multi-tenant boundaries using Cilium and Kube-OVN, providing overlay routing, BGP peering, and integrated load balancing.
- Managed database services: provisions high-availability clusters for PostgreSQL, MySQL, Redis, and ClickHouse through declarative manifests with automated backups.
- Integrated object storage: embeds S3-compatible storage powered by SeaweedFS, letting developers provision application buckets directly through cluster APIs.