Cozystack and OpenShift Virtualization both run virtual machines on Kubernetes through KubeVirt, but they differ in commercial model and scope. OpenShift Virtualization is Red Hat’s per-CPU subscription product built on the broad OpenShift platform, best for existing Red Hat and IBM customers. Cozystack is an Apache 2.0, open-source platform combining Kubernetes, KubeVirt, Cilium (eBPF) networking, and LINSTOR/DRBD storage, with nested Tenant CRD multi-tenancy, making it well suited to open-source-first organizations and service providers. Cozystack is a CNCF Sandbox project with no per-CPU licensing. Aenix, the team behind Cozystack, sells the productized Ænix Platform plus support and migration services for enterprises evaluating an OpenShift alternative or planning a Red Hat exit.
Both KubeVirt-based. Different commercial models, different operational footprints.
Pairs with: Ænix Private Cloud Platform — regulated enterprises evaluating an OpenShift alternative, including the developer self-service layer that replaces the OpenShift developer experience.
| OpenShift Virtualization | Cozystack |
|---|
| License | Red Hat commercial subscription | Apache 2.0 |
| Foundation | OpenShift + KubeVirt | Kubernetes + KubeVirt + Cilium + LINSTOR |
| Operational footprint | OpenShift broad | Cozystack focused |
| Multi-tenancy | Project CRD + namespaces | Tenant CRD (nested) |
| Vendor relationship | Red Hat / IBM | Optional: Ænix, or none — the code is Apache 2.0 either way |
| Cost model | Red Hat subscription per core pair or socket pair | Free + optional support tier |
| Best for | Existing Red Hat customers | Open-source-first, service providers |
Operators and certified images — the part that usually decides it
The comparison table understates what OpenShift customers actually buy. OperatorHub with Red Hat-certified operators, UBI base images with a supported lifecycle, and a vendor who will take a support call about a third-party operator running on their platform: that ecosystem is real, and for an organisation whose procurement requires a certified image for every workload, it settles the question. Cozystack has no equivalent certification programme and does not claim one.
What Cozystack offers instead is a smaller set of managed services maintained as part of the platform itself — PostgreSQL, MariaDB, ClickHouse, Kafka, RabbitMQ, Redis, S3, managed Kubernetes — rather than a marketplace of operators you assemble and then own. Upstream operators (CNPG, Strimzi, anything else) run on it normally; they are simply your responsibility, as they are on any Kubernetes.
One correction to the usual comparison, in Red Hat’s favour: an OpenShift Virtualization deployment does not have to be priced as full OpenShift. Red Hat sells OpenShift Virtualization Engine as a VM-only SKU, which materially changes the arithmetic for an estate that is mostly virtual machines. Compare against that SKU, not against the platform subscription, or the cost case you build will not survive contact with a Red Hat account team.
Read it this way: if your constraint is “every component must be vendor-certified and supported by one throat to choke”, OpenShift is the correct answer and this page will not change that. If your constraint is licence cost and operational surface area, the trade goes the other way.
For Red Hat shops — OpenShift Virtualization fits. For open-source-first or service-provider model — Cozystack.
See OpenShift alternative for migration guidance and OpenShift vs Cozystack article for detailed comparison.
Ænix is the team behind Cozystack.
Frequently asked questions
Are Cozystack and OpenShift Virtualization based on the same technology?
Both run virtual machines on Kubernetes using KubeVirt, so the VM layer is comparable. They diverge below that: Cozystack pairs KubeVirt with Cilium networking and LINSTOR storage on plain Kubernetes, while OpenShift Virtualization layers KubeVirt on Red Hat’s broader OpenShift platform.
How does the cost model differ?
OpenShift Virtualization is a Red Hat subscription sold per core pair or socket pair. Compare against the OpenShift Virtualization Engine SKU rather than the full OpenShift platform subscription if your estate is mostly virtual machines, because that is the cheaper and correct comparison. Cozystack is Apache 2.0 with no per-CPU or per-core licensing; you can run it free or buy the productized Ænix Platform with support, starting at Basic $1,250/mo for 10 nodes.
Is Cozystack a viable OpenShift alternative for enterprises?
Yes, particularly for open-source-first organizations and service providers, and for teams planning a Red Hat or IBM exit. Aenix offers the Private Cloud Platform and migration guidance. See the OpenShift alternative page for migration specifics.
How does multi-tenancy compare?
OpenShift uses Project CRDs and namespaces. Cozystack uses a nested Tenant CRD, which lets you carve out isolated, self-service tenants within a single cluster, a model suited to service providers and internal developer platforms.
Is Cozystack a CNCF project?
Yes. Cozystack has been a CNCF Sandbox project since 28 February 2025, with CNCF Incubating status expected in late summer 2026. It is released under Apache 2.0.
When should we choose OpenShift Virtualization over Cozystack?
If you already run Red Hat OpenShift and value the existing Red Hat support relationship and broad platform footprint, OpenShift Virtualization fits naturally. Cozystack is the stronger fit when you want open-source licensing, a focused operational footprint, or a service-provider model.
