Nutanix alternative — open source without appliance lock-in

Open-source Cozystack (a CNCF project we create and maintain) → Ænix Platform, the supported commercial distribution → Aenix builds, operates and migrates it.

The leading open-source Nutanix alternative is Cozystack, a CNCF Sandbox project that runs virtual machines and containers on a single Kubernetes API. Where Nutanix AHV is proprietary KVM tied to a certified node list and per-node subscriptions, Cozystack is Apache 2.0 licensed, runs on commodity hardware, and uses KubeVirt for VMs, Cilium (eBPF) for networking, and LINSTOR/DRBD for storage. Its Tenant CRD delivers production multi-tenancy, making it well-suited to service providers, regulated enterprises, and modern greenfield builds that Nutanix’s VM-centric model handles less directly. Aenix, the team behind Cozystack, packages it as the productized Ænix Platform with enterprise support, so organizations escaping appliance lock-in keep an open foundation while retaining commercial backing.

Quick facts

What it is An open-source, Kubernetes-native alternative to Nutanix HCI/AHV for running VMs and containers without appliance lock-in
License Apache 2.0 (no per-CPU / per-core licensing)
Status Cozystack is a CNCF project (Sandbox since 2025-02-28; Incubating expected late summer 2026)
Virtualization KubeVirt (KVM) on Kubernetes, vs Nutanix proprietary AHV
Multi-tenancy Tenant CRD, nested, with per-tenant quota and scoped audit; Nutanix uses projects and categories, which delegate well inside one organisation
Hardware Runs on commodity servers; no certified-node list to buy from. Nutanix supports Dell, HPE, Lenovo, Cisco and Fujitsu nodes, but the list is the list.
Best for Service providers, regulated multi-tenant environments, and greenfield deployments

Nutanix HCI is operationally simple, mature, and integrated. The trade-offs: closed source, appliance-led lock-in, and a subscription model that follows similar pressure dynamics to VMware. For organizations seeking comparable VM-platform capabilities with open-source foundations and multi-tenant cloud-builder features — Cozystack is the realistic alternative.

Pairs with: Ænix Private Cloud Platform — multi-DC private/hybrid sovereign cloud, customer-controlled hardware (no Nutanix appliance lock-in), DORA / NIS2 alignment.

Book a review Nutanix vs Cozystack vs VMware →

When Nutanix may not be the right answer

Closed-source concerns — sovereignty, audit-readiness, supplier-chain transparency favor open source.
Certified-node constraint — refresh happens inside Nutanix’s hardware compatibility list, across its OEM partners rather than any server you can buy.
Subscription pricing trajectory — similar dynamics to other commercial HCI vendors.
Multi-tenant service-provider model — Nutanix projects delegate well inside one organisation; a customer-facing, untrusted-tenant model needs more.
Container + VM unified workloads — Nutanix Kubernetes Platform is a second control plane beside AHV, not the same one.

If your existing Nutanix deployment is operating well and economics support continuation — stay. The alternative analysis is for organizations triggered by one of the above.

Where Nutanix is genuinely better

Nutanix has the best operational experience of any platform on this site, and it is not close. Specifically:

Appliance-grade day-2. Prism Central with one-click Life Cycle Manager upgrades that sequence firmware, hypervisor and AOS together. Cozystack upgrades are Kubernetes upgrades: declarative, but yours to sequence.
Storage that needs no design decision. Inline and post-process dedup, compression, erasure coding and tiering are in AOS, tuned, and on by default. LINSTOR/DRBD is fast and simple, and it is a design exercise.
A single accountable vendor. One support number for hardware, hypervisor, storage and management, with a support organisation that has earned its reputation. On Cozystack the hardware is yours and the platform support is a separate contract.
Adjacent products that work. Nutanix Database Service (formerly Era), Files, Objects, and Nutanix DR with Metro availability are mature and integrated.
Time to first cluster. Hours, by someone who has not read a platform-engineering book.

If Nutanix is running well and the renewal is affordable, staying is the right answer. This page is for estates where sovereignty, hardware freedom, multi-tenant service-provider requirements, or the cost of two control planes have changed that arithmetic.

Still comparing? See pricing & platforms →

Cozystack vs Nutanix AHV

	Nutanix AHV	Cozystack
License	Subscription	Apache 2.0
Foundation	Proprietary KVM (AHV)	KubeVirt (KVM) on Kubernetes
Open source	No	Full
Multi-tenancy	Projects, categories and RBAC — good delegation inside one organisation	Tenant CRD, nested, per-tenant quota and scoped audit
Containers	Nutanix Kubernetes Platform (separate product)	Native, same control plane as VMs
Hardware	Certified node list (Nutanix and OEM partners)	Commodity
Best for	Enterprises wanting one accountable vendor and the least day-2 work	Service providers, regulated multi-tenant, modern greenfield

Nutanix AHV

Proprietary KVMCertified node listPer-node subscription

replaced by

Cozystack

KubeVirt (KVM)Cilium (eBPF)LINSTOR/DRBDTenant CRD

runs on

Commodity hardware

No certified-hardware requirementService providersRegulated multi-tenant

Book a call

Ænix is the team behind Cozystack.

Frequently asked questions

What is the best open-source alternative to Nutanix?

Cozystack is the realistic open-source alternative. It is Apache 2.0 licensed, runs VMs and containers on a single Kubernetes API via KubeVirt, and provides production multi-tenancy through its Tenant CRD without Nutanix’s appliance lock-in or per-node subscription model.

How does Cozystack compare to Nutanix AHV?

Nutanix AHV is proprietary KVM on subscription, running on a certified node list across Nutanix and OEM hardware. Containers are covered by Nutanix Kubernetes Platform, a separate product rather than the same control plane. Cozystack is open-source KubeVirt on Kubernetes, runs on commodity hardware, runs VMs and containers on one API, and offers production multi-tenancy via the Tenant CRD.

Can Cozystack run both virtual machines and containers?

Yes. Cozystack runs VMs through KubeVirt and containers natively on the same Kubernetes API, so unified container-plus-VM workloads are first-class. Nutanix covers containers through Nutanix Kubernetes Platform, which is a capable product but a separate control plane to operate and license.

Should I migrate off Nutanix?

Not always. If your Nutanix deployment runs well and the economics support it, staying is reasonable. The alternative analysis is for organizations triggered by closed-source sovereignty concerns, appliance lock-in, subscription pricing trajectory, or a need for a multi-tenant service-provider model.

Does Aenix offer commercial support for Cozystack?

Yes. Aenix is the team behind Cozystack and sells the productized Ænix Platform with enterprise support. Plans start at Basic $1,250/mo for up to 10 nodes, then Standard $3,000 and Plus $5,500, with an Enterprise Custom tier.

What networking and storage does Cozystack use?

Cozystack uses Cilium (eBPF) for networking and LINSTOR with DRBD for replicated block storage, both running on commodity hardware. This contrasts with Nutanix’s integrated proprietary stack tied to its appliance model.