Comparison · Aug 21, 2026

Proxmox vs oVirt: which open-source virtualization platform has a future?

Proxmox VE or oVirt for open-source datacenter virtualization? One has a company behind it, one lost its backer. Plus the API differences we measured on both.

By Provibr

Whether you type it as oVirt vs Proxmox or Proxmox vs oVirt, the order usually says which one you already run. Both are open-source, KVM-based platforms that will run a cluster of virtual machines with live migration, high availability and shared storage, and on the feature checklist they look close. But there is a question underneath the checklist that matters more than any single feature, and it is not about features at all. It is about who is still building the thing.

Provibr manages both live: Proxmox first, and oVirt as the first non-Proxmox hypervisor we integrated. So the operational details below are measured, and where we are talking about the projects' direction rather than their APIs, that is public information with a source attached.

The question underneath: who is behind it

oVirt is the upstream community project behind Red Hat Virtualization (RHV), the commercial product Red Hat sold for years. Red Hat has stepped away from that product.

Red Hat Virtualization reached the end of its maintenance support phase, with Red Hat directing customers toward OpenShift Virtualization as the successor. The commercial product is being wound down rather than developed.
https://access.redhat.com/support/policy/updates/rhev · 2026-08-21

oVirt continues as a community project with no announced end of life, but with community prioritisation rather than the resources of a vendor's flagship product, and its development moved to community infrastructure on GitHub.
https://www.ovirt.org/ · 2026-08-21

Proxmox VE is the opposite story. It is the flagship product of a company that sells support and releases updates on a regular cadence, and it is free and open source at the same time.

Proxmox VE is free and open-source software (AGPLv3); every feature is available at no cost. An optional subscription, from about €120 per CPU socket per year (Community) to about €1,100 (Premium), buys access to the stable enterprise update repository and support, not extra features.
https://www.proxmox.com/en/products/proxmox-virtual-environment/pricing · 2026-08-21

That is the difference that outlasts any feature comparison. One of these platforms is a company's active product with a paid support option; the other is a community carrying on a codebase after its corporate sponsor moved on. For a new deployment, and especially for a hosting business that has to bet on the platform being maintained for years, that weighs heavily toward Proxmox.

What they have in common, and where they diverge in shape

Both run KVM. Both give you a datacenter, cluster and host model, live migration, HA and storage domains. The architecture differs in weight: oVirt's engine is a heavier stack (a Java engine, a management database and a VDSM agent on each host), while Proxmox is a lighter Debian-based system with a web interface built into every node and no separate engine to run.

Everything below we measured against a running oVirt 4.5.7 install and against Proxmox in production.

Subject	Proxmox VE	oVirt
Software licence	free, open source (AGPLv3)	free, open source
Vendor behind it	Proxmox Server Solutions, active	Red Hat, stepped back (RHV wound down)
How a VM is addressed	a small integer vmid	a UUID
Choosing where a VM runs	you pick the node	the engine picks the host
Web UI	built into every node	a separate engine portal
API credential	a revocable, non-expiring API token	username + password only
Session model	token in a header, no login step	password grants a 7-day SSO token, no refresh endpoint
Token expiry behaviour	none	expiry returns HTML, not JSON, on the next call
Engine components to run	none beyond the nodes	a Java engine + a management database

Two of those rows are worth more than a cell.

Proxmox has a proper machine credential; oVirt does not. Proxmox issues an API token: a token id and secret you can scope and revoke, and it does not expire. oVirt has no equivalent long-lived, revocable token. The only credential is a username and password, which you exchange for an SSO bearer token that lives seven days with no way to refresh it; when it expires you authenticate again. That means the credential an integration has to store for oVirt is a full account password rather than a scoped token, which is a stronger secret to be holding, and the sensible mitigation is a dedicated, limited oVirt user rather than the admin account.

oVirt tells you a token expired in HTML. When the seven-day token lapses mid-command, the API answers 401 with an HTML body, not the JSON fault you would expect from a REST API. A client that blindly parses JSON on a 401 falls over on exactly the response it needs to understand. Because the token lives a week this is rare, but an agent that runs for months has to re-authenticate on a 401 and retry once. Proxmox has none of this. The token simply keeps working.

So which one should you pick?

Pick Proxmox VE if you are deploying new, you want a platform that is actively developed and commercially supportable without being locked behind a licence, and you value a lighter stack. For a hosting business selling VPS, this is the clearer bet, and it is where the momentum is.

Consider oVirt if you are already an oVirt or RHV shop with deep operational investment and the in-house knowledge to run the engine, and you are comfortable relying on community maintenance rather than a vendor. It is a capable platform; the concern is longevity and support, not capability.

If you are leaving RHV, the real decision is not oVirt versus Proxmox so much as which platform you migrate to. Many teams in that position are evaluating Proxmox precisely because it offers the commercial support and active development that RHV no longer will.

Where a management layer fits

Provibr drives both platforms today: creating, running and metering virtual machines, and turning a cluster into a customer-facing product with billing, capacity limits and reseller controls. To be plain about the difference in mileage: Proxmox we run in production, and the oVirt integration was built and measured against a running 4.5.7 installation.

That matters for the migration story. If you are moving off RHV or oVirt to Proxmox, the platform underneath changes but the thing your customers see does not have to be built from scratch. Provibr gives you one panel, one inventory and one invoice over the new estate, with the agent dialling outward from your own network so nothing needs an inbound port opened. The hypervisor decision is yours; the layer that sells it is where we come in.

Frequently asked questions

Is oVirt still maintained?

oVirt continues as a community project with no announced end of life, but Red Hat has wound down the commercial product built on it and points customers at OpenShift Virtualization instead. Both statements carry their source and the date we checked them in the section on who is behind each platform.

Can Provibr manage oVirt as well as Proxmox?

Yes. Both are live integrations. The measurements on this page come from Proxmox in production and from a running oVirt 4.5.7 installation.

What is the biggest practical difference between the two APIs?

The credential. Proxmox issues a scoped, revocable API token that does not expire; oVirt has no equivalent, so the only credential is a username and password that you exchange for an SSO token valid seven days with no refresh endpoint.

Why does an expired oVirt token break a naive client?

Because the API answers 401 with an HTML body instead of the JSON fault a REST client expects. Anything that blindly parses JSON on a 401 falls over on exactly the response it needs to read, so an agent that runs for months has to re-authenticate on a 401 and retry once.