What is OpenStack?

In practical terms, it lets enterprises virtualize compute, storage, and networking resources in a way that closely resembles public cloud services while maintaining full control over where workloads run and how data is handled.

OpenStack provides infrastructure-as-a-service (IaaS) capabilities; users interact with OpenStack through a web-based dashboard, command-line tools, and APIs to provision and manage virtual machines, networks, and storage. This accelerates application development and infrastructure operations while improving hardware utilization. Depending on how it is deployed, OpenStack can also serve as a foundation for developer environments, container platforms, and Kubernetes clusters that run on top of OpenStack-managed virtual infrastructure.

Administrators can define access controls, allocate resources across teams or tenants, and automate common infrastructure tasks. Many OpenStack environments also expose higher-level services such as database-as-a-service, application catalogs, and managed Kubernetes. Because OpenStack runs as a private cloud, organizations retain full control over data placement, security controls, and compliance posture. This level of control is difficult or costly to achieve in shared public cloud environments.

The primary tradeoff is operational responsibility, since organizations must purchase and operate their own infrastructure and cloud platform. However, modern OpenStack distributions, managed services, and Kubernetes-based control planes have significantly reduced deployment and operational complexity. Today, it is increasingly possible to consume OpenStack “as a service,” while keeping infrastructure on-premises or in dedicated environments.

What are the Benefits of OpenStack?

Most organizations adopt OpenStack to deliver public cloud–like agility within a private or controlled environment. While specific drivers vary by industry and workload, OpenStack is commonly chosen for the following reasons:

Privacy and Data Control

OpenStack enables strict control over who can access infrastructure resources and how data is stored, moved, and encrypted. This level of control is often required to meet regulatory compliance, data residency mandates, and internal governance standards.

Performance and Efficiency

In an OpenStack environment, organizations control how infrastructure is configured and how workloads run. This makes it possible to tune compute, storage, and networking to achieve the desired balance between performance and resource utilization.

Because the underlying hardware is dedicated, performance characteristics are more predictable than in multi-tenant public clouds, which is especially important for latency-sensitive or resource-intensive workloads.

Flexibility

OpenStack runs on a wide range of compute, storage, and networking hardware and integrates with many existing enterprise systems. This allows organizations to design clouds optimized for very different use cases, from high-performance environments with CPU- and GPU-dense nodes to cost-efficient platforms built on commodity hardware.

This architectural flexibility makes OpenStack suitable for diverse workloads, including machine learning, scientific computing, media processing, telecom infrastructure, and traditional enterprise applications.

Cost Predictability

While on-premises cloud infrastructure requires upfront investment in hardware and facilities, OpenStack offers long-term cost predictability. Once infrastructure is in place, ongoing costs are largely fixed and easier to forecast.

By contrast, public cloud costs often increase unpredictably as environments grow, services accumulate, and usage patterns change. As a result, many organizations are now repatriating steady-state or data-intensive workloads from public clouds back to private OpenStack environments to regain cost control.

Open-Source Foundation

OpenStack is open source, meaning its source code is publicly available and continuously improved by a global community of contributors. This accelerates innovation, enables rapid security patching, and provides transparency into how the platform works.

Open source also reduces dependency on a single vendor. OpenStack can run on multiple Linux distributions and a broad range of hardware, allowing organizations to avoid being locked into a specific operating system, infrastructure vendor, or licensing model.

Most enterprises do not deploy OpenStack directly from upstream code; instead, they use vendor-supported distributions like Mirantis OpenStack for Kubernetes that package OpenStack with deployment tooling, security hardening, and lifecycle support. As with Linux distributions, buyers should evaluate how much lock-in a given distribution introduces, particularly around operating systems, hardware, or proprietary extensions.

Scalability

OpenStack is designed to scale horizontally as infrastructure needs grow. Organizations can expand capacity by adding additional compute, storage, or networking resources and integrating them into the existing cloud. Because OpenStack itself does not impose significant licensing costs, it is well suited for building large-scale on-premises cloud infrastructure with a lower long-term total cost of ownership than proprietary alternatives. 

High Availability and Reliability

OpenStack includes native mechanisms for high availability and fault tolerance across both the control plane and the workloads it manages. Services can be deployed redundantly to avoid single points of failure, and workloads can be automatically recovered when underlying infrastructure components fail.

Modern OpenStack distributions further enhance availability by running the OpenStack control plane in containers, often on Kubernetes. This allows individual services to scale horizontally, restart automatically, and be upgraded with minimal disruption, improving resilience and operational stability.

Multi-Tenancy

OpenStack provides strong multi-tenancy capabilities that allow a single cloud to be securely shared across teams, departments, or even external customers. Administrators can define tenants, projects, roles, and quotas to control resource usage and enforce isolation.

These features make it possible to allocate resources precisely, guarantee performance, and meet security requirements while still maximizing utilization of shared infrastructure. This is one reason OpenStack is widely used by service providers and organizations that operate large, multi-user environments.

APIs and Automation

OpenStack exposes comprehensive APIs and command-line tools that allow infrastructure operations to be fully automated. Software development kits are available for most major programming languages, and OpenStack integrates well with popular automation tools such as Ansible.

For organizations operating multiple cloud environments, including OpenStack, VMware, and public clouds, this API-driven model makes it possible to reuse automation patterns and workflows across platforms, reducing operational friction.

Who Uses OpenStack?

OpenStack is widely adopted across industries and deployment models. Most commonly, organizations use OpenStack to build on-premises cloud infrastructure in one or more data centers, but its flexibility makes it suitable for many other scenarios as well.

Enterprise On-Premises Cloud Infrastructure

Enterprises use OpenStack to create internal cloud platforms that deliver self-service infrastructure while maintaining strict control over security, compliance, and cost. These environments often support a mix of legacy and modern applications.

Public Cloud Providers

A number of public cloud providers use OpenStack as the foundation for their infrastructure, offering virtual machines, storage, and networking services to customers on a pay-per-use basis. Examples include providers such as Rackspace, OVH, and DreamHost.

Hybrid and Multi-Cloud Environments

OpenStack is frequently combined with public cloud services to create hybrid environments. It provides tools and APIs that help manage resources across private and public clouds and support workload migration between them.

Research and Scientific Computing

OpenStack evolved out of original work by NASA, Rackspace, and early adoption by organizations like CERN, and has many users in universities and research institutions. It’s found frequently in scientific computing environments, where it manages compute and storage resources for large-scale simulations, data analysis, and other scientific applications. OpenStack's ability to scale and customize to specific needs makes it ideal for these demanding use cases.

Telecom, Service Providers, and Edge Clouds

Telecommunications providers and service operators often choose OpenStack to build large-scale or geographically distributed clouds. OpenStack can integrate efficiently with specialized hardware such as high-performance network interfaces and GPUs, making it well suited for network functions virtualization, edge computing, and low-latency services. It is also commonly used to host Kubernetes clusters and containerized network functions.

Government and Public Sector Organizations

Government and public sector entities use OpenStack to build on-premises cloud infrastructure that meet stringent requirements for security, transparency, and control. Open source platforms are often preferred in these environments for their flexibility and auditability.

OpenStack Architecture

OpenStack is composed of a set of modular services that work together to deliver infrastructure-as-a-service capabilities. Each service is responsible for a specific function, and the platform is designed so these components can be scaled, extended, or replaced as needed.

Horizon (Dashboard)

Horizon provides a web-based graphical interface for OpenStack. It allows administrators and users to manage cloud resources such as instances, networks, volumes, and projects without relying exclusively on command-line tools. Horizon is commonly used for day-to-day operational tasks and tenant administration.

Nova (Compute)

Nova is responsible for managing the lifecycle of virtual machine instances. It supports multiple hypervisors, most commonly KVM, and is designed to scale to support large numbers of virtual machines across many physical hosts.

Cinder (Block Storage)

Cinder provides persistent block storage volumes that can be attached to running instances. It supports snapshots and integrates with a wide range of storage backends, including local disks, network-attached storage, and storage area networks. This flexibility allows operators to tailor storage performance and cost characteristics to different workloads.

Neutron (Networking)

Neutron enables software-defined networking within OpenStack. It allows operators to define virtual networks, subnets, routers, gateways, and IP address management policies. Neutron supports common networking technologies such as VLANs and overlay networks, enabling flexible and isolated networking configurations.

Keystone (Identity)

Keystone provides authentication and authorization services for OpenStack. It manages users, roles, and permissions, and integrates with external identity providers such as LDAP, Active Directory, and OAuth. Keystone enables fine-grained access control and supports advanced security models, including zero trust architectures.

Glance (Images)

Glance manages virtual machine images that are used to launch instances. Images typically contain a bootable operating system and may be preconfigured to meet organizational standards. Glance supports multiple image formats, including ISO, QCOW2, and VMDK, and allows operators to control which images are available to users.

Additional OpenStack Services

Beyond these core components, the OpenStack ecosystem includes a large number of optional services that add capabilities such as DNS-as-a-service, database-as-a-service, and application orchestration. These services integrate with the core platform to create richer and more developer-friendly cloud environments.

Modern OpenStack distributions increasingly deploy the OpenStack control plane itself as containerized services, often running on Kubernetes. This approach improves scalability, resilience, and upgradeability, and simplifies ongoing operations.

OpenStack vs. AWS

OpenStack and AWS are often evaluated together by organizations designing hybrid cloud strategies or reassessing long-term cloud costs.

Shared Capabilities

Both platforms provide core infrastructure services such as compute, storage, and networking, along with APIs and command-line tools for automation. Both can be used as part of hybrid cloud architectures that combine on-premises and off-premises resources.

Open Source Versus Proprietary Platforms

OpenStack is an open-source platform that can be customized and extended without licensing restrictions. AWS is a proprietary platform, and its services are tightly integrated into the AWS ecosystem.

Lock-In Considerations

AWS offers a broad portfolio of managed services that can significantly accelerate application development. However, heavy reliance on these services can increase switching costs and make it difficult to migrate workloads elsewhere. OpenStack environments typically rely on open standards and open-source components, which reduces long-term lock-in risk.

Scalability Models

AWS provides near-instant access to massive global capacity, which can be valuable for workloads with highly variable or unpredictable demand. OpenStack scalability depends on adding physical infrastructure, which requires planning and procurement. In practice, many enterprise workloads grow at a steady and predictable pace, making it viable to scale on-premises cloud infrastructure.

Cost 

OpenStack offers predictable costs tied to owned infrastructure and operational expenses. AWS uses a consumption-based pricing model that can be difficult to forecast as environments grow and services accumulate. For this reason, organizations often use a mix of OpenStack and AWS, placing stable workloads on private infrastructure and bursty workloads in the public cloud.

OpenStack vs. VMware

OpenStack and VMware are frequently compared because they represent the two most popular approaches to enterprise on-premises infrastructure available to buyers today. In the current era, many organizations see OpenStack as a more modern, flexible, and cost-effective alternative to VMware (long favored by large enterprises) because of rising costs, proprietary licensing, and uncertainty about support in the aftermath of VMware’s acquisition by Broadcom.

Platform Approach

VMware provides a tightly integrated, proprietary virtualization stack designed to run on certified hardware and supported configurations. OpenStack offers a modular, open architecture built around open standards and a broad ecosystem.

Open Source Versus Proprietary Platforms

VMware licensing is proprietary and can become complex and costly as additional capabilities are added, including Kubernetes platforms such as Tanzu. OpenStack distributions typically focus pricing on support and services rather than per-core or per-feature licensing, which can result in more predictable long-term costs.

Hardware and Operating System Flexibility

VMware environments often depend on certified hardware and a limited set of supported host operating systems. OpenStack supports a wider range of hardware platforms and Linux distributions, giving organizations greater flexibility in how they design and source infrastructure.

Kubernetes Support

Both VMware and OpenStack support Kubernetes, but they approach it differently. VMware delivers Kubernetes through tightly integrated products, while OpenStack commonly hosts Kubernetes clusters or runs its own control plane on Kubernetes, depending on the distribution.

OpenStack and Kubernetes

OpenStack and Kubernetes are complementary platforms that address different layers of the cloud stack. OpenStack is typically used to manage virtualized infrastructure and provide infrastructure services, while Kubernetes focuses on orchestrating containerized applications. OpenStack can host Kubernetes clusters, and Kubernetes can host containerized OpenStack control plane services.

This layered model allows organizations to combine mature virtualization with cloud-native application platforms, rather than choosing one at the expense of the other.

OpenStack Complexity

OpenStack's key features make it a highly versatile and customizable cloud computing platform that can meet the needs of a wide range of organizations and use cases, but this flexibility and power comes with tradeoffs:

Operational Complexity

Deploying and operating OpenStack requires specialized skills in areas such as networking, storage, security, and automation. This can create a steep learning curve for platform teams. Many organizations mitigate this complexity by using vendor-supported distributions, automation tooling, or managed services.

Potential for Lock-In

Although OpenStack itself is open source, lock-in can still occur through proprietary extensions, hardware dependencies, or tightly coupled integrations. The most flexible OpenStack platforms emphasize open components and interchangeable infrastructure, reducing long-term risk.

OpenStack Training and Certification

OpenStack offers a comprehensive training and certification program for developers and IT professionals. The program includes various courses that cover OpenStack's fundamentals, architecture, deployment, and management.

You can also take certification exams that validate your OpenStack proficiency so current and future prospective employers can have more confidence in your skills. Certification exams are available for different roles, such as OpenStack Administrator, OpenStack Developer, and OpenStack Architect.

OpenStack certification is recognized globally and demonstrates your expertise in OpenStack. It can be an excellent way to enhance an IT professional's career prospects and improve an organization's OpenStack adoption and management.

Production-Ready OpenStack: A Kubernetes-Native Approach

OpenStack provides a powerful foundation for building private and hybrid clouds, giving organizations control over infrastructure, costs, and data. But operating OpenStack reliably in production requires more than understanding its components. It requires an operational model that is resilient, upgradeable, and aligned with modern cloud-native practices.

Mirantis OpenStack for Kubernetes (MOSK) is a Kubernetes-native OpenStack platform designed to simplify OpenStack operations without sacrificing enterprise-grade capabilities. By running the OpenStack control plane on Kubernetes, MOSK modernizes how OpenStack is deployed, managed, and scaled.

Key features include:

• Kubernetes-Native OpenStack Architecture: OpenStack services run as containerized workloads on Kubernetes, improving resilience, scalability, and lifecycle management

• Simplified Operations and Upgrades: Kubernetes-based orchestration reduces operational complexity and enables safer, more predictable updates across the OpenStack control plane

• Flexible Deployment Models: MOSK supports a wide range of environments, from centralized datacenters to distributed and edge deployments

• Open, Standards-Based Platform: Built on upstream OpenStack and Kubernetes, MOSK avoids proprietary lock-in and maintains compatibility with standard tools and workloads

• Build-Operate-Transfer Delivery Model: Let Mirantis experts build and manage OpenStack cloud infrastructure to meet your business requirements, with the option to transfer operations to your team when you’re ready.

If you are looking to modernize OpenStack operations while maintaining full control over your on-premises cloud infrastructure, MOSK provides a streamlined path forward. Start exploring MOSK today!