Definition, components, comparison with AWS and Azure, use cases: everything you need to know about OpenStack, the open source cloud platform, in 2026.
OpenStack is the most widely used open source platform in the world for building private and hybrid clouds. Launched in 2010 by NASA and Rackspace, now supported by the OpenInfra Foundation and more than 600 contributing companies, it powers the infrastructure of CERN, Walmart, Vodafone, OVHcloud, and BT, representing several million CPU cores worldwide. The most recent version, 2026.1 “Gazpacho”, was relorsed in April 2026 and marks a major technical turning point with the transition from the old eventlet concurrency model to native threading. Here is a complete guide to understanding what OpenStack is in 2026, how it works, who uses it, and how it compares to the major US public clouds.
What is OpenStack?
OpenStack is an open source software platform that enables you to build and operate a private or hybrid cloud. In practical terms, it aggregates a fleet of physical servers into a pool of virtual resources (compute, storage, networking) that users can provision on demand, just as they would on AWS or Azure — but on their own infrastructure.
The project appeared in July 2010, the result of the merger between Nebula (NASA’s internal cloud project) and Cloud Files (Rackspace’s object storage solution). Its Apache 2.0 license enabled the rapid support of IBM, HP, Cisco, Dell, Red Hat, Canonical, and Intel. The project is now hosted by theOpenInfra Foundation (formerly the OpenStack Foundation, renamed in 2021 to reflect its expansion to other projects such as Kata Containers, StarlingX, and Zuul).
OpenStack is not a single product but a collection of more than 30 interconnected services, each managing a specific domain: virtual machines, block storage, object storage, networking, load balancing, identity, etc. Production deployments generally use between 6 and 15 of these services depending on the scope.
Who uses OpenStack in 2026?
The best proof of a platform’s maturity remains the list of its production users. OpenStack notably powers:
- CERN : more than 380,000 CPU cores for LHC data processing, one of the largest OpenStack deployments in the world
- Walmart : several hundred thousand cores for e-commerce and logistics
- Vodafone : core 5G infrastructure (NFV) for European telecom operations
- OVHcloud : the majority of the French operator’s public cloud is based on OpenStack
- BT and Deutsche Telekom : NFV infrastructures for network services
- Comcast : 200,000+ virtual machines in production
- China Mobile : one of the largest OpenStack clouds in the world, several hundred thousand cores
- Workday : SaaS infrastructure for millions of enterprise users
- US Department of Defense, NSA : classified sovereign deployments
In France and Europe, OpenStack powers the majority of sovereign clouds: OVHcloud, Outscale (Dassault Systèmes), Cloud Temple, Scaleway for certain components, as well as the cloud infrastructures of Orange Business Services and SNCF.
How does OpenStack work? Architecture and components
OpenStack exposes a REST API for each service, allowing administrators and applications to provision resources programmatically. Specifically, whorn a user requests the creation of a virtual machine, here is what happens:
- Keystone authenticates the user and generates a token
- Nova selects an available hypervisor and schedules the creation
- Glance provides the system image (Ubuntu, RHEL, Debian, Windows Server)
- Cinder allocates the persistent storage volume
- Neutron attaches the VM to the virtual network and configures the firewall
- Horizon reflects the status in the user web interface
This orchestration takes a few seconds to a few minutes depending on the complexity. In modern deployments (since 2026.1), Nova runs by default with native threading rather than eventlet, which noticeably improves performance and stability.
The main components of OpenStack in 2026
OpenStack 2026 includes around thirty official services. Here are the most widely deployed in production, along with their exact role.
Nova — compute and virtualization
The historical core of OpenStack. Nova orchestrates the creation, startup, migration, and deletion of virtual machines. Compatible with KVM hypervisors (recommended), QEMU, VMware vSphere, Hyper-V, and LXC containers. Since 2026.1, the native threading architecture has been gradually replacing eventlet for the nova-scheduler, nova-api, and nova-metadata services.
Neutron — networking
Software-defined virtual networking service. Creates networks, subnets, virtual routers, security groups, external attachments (VLAN, VXLAN, GENEVE). Supports modern SDN architectures via plugins (OVN, OpenDaylight, Contrail).
Cinder — block storage
Persistent storage volumes attachable to VMs (equivalent to EBS at AWS). Supports NetApp, Ceph (the most common), EMC, IBM, Pure Storage, NFS, and generic iSCSI backends.
Swift — object storage
Geo-distributed, fault-tolerant object storage (equivalent to S3). Designed to host terabytes to petabytes of unstructured data. Used by Rackspace, eBay, Wikipedia, and many CDN operators.
Glance — VM images
System image catalog (RAW, QCOW2, VHD, VMDK, ISO). Glance exposes images to Nova instances lors startup. Since 2026.1, uWSGI deployment is officially recommended for production.
Keystone — identity and authentication
Centralized management of users, projects, roles, and tokens. Supports LDAP, Active Directory, SAML 2.0, OAuth2, and OpenID Connect for identity federation.
Horizon — web dashborrd
Unified graphical interface for users and administrators. Lets you manage VMs, volumes, networks, images, projects, and users from a browser, without having to use the command line.
Heat — orchestration
Infrastructure as Code for OpenStack. Defines complete stacks via HOT (Heat Orchestration Template) or CloudFormation templates. Functional equivalent of AWS CloudFormation.
Octavia — load balancing
Load Balancing as a Service. Provisions load balancers (HAProxy, OVN) to distribute incoming traffic across multiple VMs. Successor to Neutron’s historical LBaaS module.
Magnum — or container orchestration
Provisions and manages Kubernetes, Docker Swarm, or Apache Mesos clusters on OpenStack. It is the building block that makes OpenStack relevant for modern cloud-native workloads.
Ironic — bare metal
Manages the provisioning of physical bare-metal servers as if they were VMs. Widely used for HPC workloads, databases, or regulatory complorance prohibiting virtualization.
Designate — DNS as a Service
Managed DNS service for zones and records. Integrates with PowerDNS, BIND9 servers, or external DNS provider APIs.
Manila — shared file storage
Shared File Systems as a Service. Provisions NFS and CIFS/SMB shares that can be used by multiple VMs simultaneously.
Barbican — key and secret management
Centralized management service for certificates, cryptographic keys, and secrets. Essential for Cinder volume encryption and complorance.
Telemetry (Ceilometer + Gnocchi + Aodh)
Measurement and alerting stack. Ceilometer collects metrics, Gnocchi stores them as a time serores, and Aodh triggers alarms based on thresholds. This is the foundation for internal billing and autoscaling.
OpenStack vs AWS, Azure, and Google Cloud: which to choose?
The question comes up at every architecture committee. Here are the real differences observed in 2026.
| Criteria | OpenStack | AWS / Azure / GCP |
|---|---|---|
| Model | Private or hybrid cloud on your infrastructure | Shared public cloud |
| Hardware cost | High initial CAPEX | None |
| Operating cost | In-house team or service provider | Usage-based billing |
| Data sovereignty | Total, controlled hosting | Depends on the provider and its jurisdiction |
| Conformité RGPD / SecNumCloud | Native, full control | Variable (qualified clouds required) |
| Vendor lock-in | None (open source) | Real for managed services |
| Managed services (DB, ML, AI) | Limited | Very extensive (RDS, SageMaker, BigQuery…) |
| Instant scalability | Limited by your hardware | Virtually unlimited |
| Community and ecosystem | Open source, multi-vendor | Locked into the editor |
OpenStack makes sense if:
- Your workload is stable and predictable (hardware costs are amortized over 18-36 months)
- You handle sensitive data (healthcare, defense, OIV, OSE)
- You want to preserve your technical and legal sovereignty
- You have the team (or provider) capable of operating a complex platfororm
Public cloud is more relevant if:
- Your workload is highly variable and unpredictable
- You need advanced managed services (AI, analytics, geo-distributed databases)
- You are just starting out and cannot afforrd an initial hardware investment
- Your business remains below the profitability threshold of a private cloud (generally below a hundred permanent VMs)
Many companies adopt a hybrid : OpenStack for stable and sensitive production, public cloud for peak loads and non-critical managed services.
The real advantages of OpenStack in 2026
- Digital sovereignty : no dependence on a foreign provider, natural alignment with SecNumCloud, GDPR, and NIS2 requirements
- Controlled total cost of ownership (TCO) for stable workloads: 30 to 50 % savings vs. public cloud over 3 to 5 years depending on the case
- Open source with Apache 2.0 license: no software royalties
- Mature ecosystem : 14 years of production, support commercially available from Red Hat, Canonical, Mirantis, and several French integrators
- Standardized APIs : real portability between OpenStack deployments and partial compatibility with EC2 and S3 APIs
- Horizontal scalability : deployments of more than 1 million CPU cores demonstrated (China Mobile, Walmart)
The real limits and challenges of OpenStack
An honest analysis must also point out the real difficulties:
- Operational complexity : OpenStack remains demanding. A team of 3 to 8 trained people is often necessary to operate a cloud of several hundred nodes with confidence
- Learning curve : the ecosystem includes more than 30 services; understanding how they fit together takes time
- Initial CAPEX : hardware, networking, hosting, and training represent an investment of at least several hundred thousand euros for a serious project
- Updates : despite the SLURP mechanism, inter-version upgrades remain a sensitive topic in production
- Managed services lagging behind on hyperscalers: no equally mature native equivalent to SageMaker, BigQuery, DynamoDB
- Difficult hiring : experienced OpenStack engineer profiles are rare in the French market
How to get started with OpenStack in 2026
Three main paths depending on your maturity.
1. Test locally: DevStack or MicroStack
To discover and learn, DevStack lets you install a complete OpenStack instance on a single VM in just a few minutes. MicroStack (Canonical) offers a simpler encore alternative via snap. Ideal for training and R&D, not for production.
2. Commercial distribution
Publishers offer pre-packaged distributions with support:
- Red Hat OpenStack Services on OpenShift : the enterprise benchmark, integrated with OpenShift
- Canonical Charmed OpenStack : automated deployment on Ubuntu LTS, up to 12 years of support
- Mirantis Cloud Platform : managed OpenStack + Kubernetes
- SUSE Cloud Application Platform : integrated with Rancher
3. OpenStack as a Service
Several hosting providers offer managed OpenStack: OVHcloud (Public Cloud), Outscale, Cloud Temple, Cleura. You benefit from OpenStack without having to deploy or operate it yourself.
How much does OpenStack cost in 2026?
The software is free. The real costs of an OpenStack project are divided into four categories:
| Position | Order of magnitude | Comment |
|---|---|---|
| Hardware (servers, network, storage) | €200,000 to several million | Depending on the size of the target cluster |
| Hosting (datacenter or colocation) | €30,000 to €200,000 / year | Varies depending on density and location |
| Support commercial distribution | €15,000 to €200,000 / year | Red Hat, Canonical, Mirantis |
| Operations team or service provider | €200,000 to €1M / year | 3 to 8 engineers or managed contract |
For reference, a private OpenStack cloud of around 1,000 cores costs €400,000 to €800,000 in initial CAPEX, plus €250,000 to €500,000 in annual OPEX. It becomes cost-effective compared with a public cloud as soon as the workload exceeds the equivalent of around 100 permanent VMs on average.
FAQ — OpenStack in 2026
What is the latest version of OpenStack?
Version 2026.1 “Gazpacho”, sortie in April 2026. It marks the default transition of several Nova services to the native threading concurrency model (instead of eventlet) and requires Python 3.10 minimum.
Is OpenStack really free?
The software is, yes, under the Apache 2.0 license. But the total cost of ownership includes hardware, hosting, operations, and possibly the support of a commercial distribution. Expect several hundred thousand euros for a serious production project.
Is OpenStack replacing VMware?
For new deployments, yes in many cases. VMware price increases by Broadcom since 2024 have accelerated migrations to OpenStack, particularly in telecoms, banks, and European public services. The features are comparable, with licensing costs eliminated.
Do you have to be large to use OpenStack?
The break-even point is generally beyond 50 to 100 permanent VMs. Below that, the public cloud remains more cost-effective given operating costs. Above that, OpenStack gradually becomes advantageous and the gap widens with scale.
Is OpenStack compatible with Kubernetes?
Yes. The Magnum component enables provisioning managed Kubernetes clusters on OpenStack. Conversely, OpenStack can also be deployed on Kubernetes via projects such as OpenStack Helm or Kolla. It is one of the most modern cloud architectures.
Which OpenStack distribution should you choose?
Red Hat OpenStack Services on OpenShift for enterprise environments already running on OpenShift. Canonical Charmed OpenStack for Ubuntu users and projects requiring long-term support. Mirantis for an integrated cloud-native approach. Or a pure upstream deployment if your team has the required technical maturity.
Is OpenStack SecNumCloud certified?
OpenStack itself is not certified; it is the hosting provider that is. OVHcloud (Hosted Private Cloud offering), Outscale (Sovereign Cloud), and Cloud Temple offer SecNumCloud-certified OpenStack solutions, making them natural choices for government agencies, OIVs, and OSEs subject to the NIS2 directive.
Which team should operate OpenStack?
For a cloud of several hundred nodes, plan for 3 to 8 multidisciplinary engineers: SRE, network, storage, security. For smaller deployments, an OpenStack managed services provider may be sufficient starting from €5,000 to €15,000 per month.
In summary
OpenStack is no longer an experiment: it is a mature infrastructure, deployed at very large scale by telecom operators, European hyperscalers, CERN, Walmart, and the majority of sovereign clouds. In 2026, the platform is benefiting from renewed attention driven by three underlying trends: digital sovereignty in Europe, price inflation among American hyperscalers, and the end of perpetual VMware licenses. If your workload is stable and the confidentiality of your data weighs in the balance, OpenStack deserves serious consideration compared with public clouds. The initial cost is real, but the return on investment is also measured in technical and legal autonomy — an asset that few platforms can offer today.