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OpenStack

The industry-standard open-source cloud operating system for building and managing large-scale private and public cloud infrastructure (IaaS).

Overview

OpenStack is a modular, service-oriented cloud platform that treats the data center as a single programmable resource pool. It provides APIs and tools for managing compute, storage, and networking resources at massive scale. Governed by the OpenInfra Foundation (formerly OpenStack Foundation), it is deployed by thousands of organizations worldwide, from telecom providers to research institutions to enterprises replacing VMware.

Repository & Community

Attribute Detail
Repository opendev.org/openstack
Latest Version 2026.1 "Gazpacho" (April 1, 2026) — SLURP release
Language Python
License Apache 2.0
Governance OpenInfra Foundation
Contributors 10,000+ (all time)

Evaluation

  • Why it's better: The most mature, feature-complete open-source IaaS platform. Full-stack infrastructure management (compute, network, storage, identity, images, orchestration). Massive community, proven at hyperscale (100k+ cores). Key VMware replacement in the post-Broadcom era.

  • When it fits (Applicability):

  • Large-scale private cloud (1,000+ nodes)
  • Telecom NFV infrastructure
  • VMware replacement / migration
  • Multi-tenant cloud service provider
  • Bare metal provisioning (via Ironic)

  • Scientific computing / HPC clusters

  • Pros and Cons:

Pros Cons
Most mature open-source IaaS Very high operational complexity
Apache 2.0, no vendor lock-in Requires dedicated platform team
Massive community & ecosystem Many moving parts (30+ projects)
Proven at hyperscale Steep learning curve
VMware migration path Eventlet → async migration ongoing
SLURP releases for stability Upgrade complexity between releases
Bare metal via Ironic Heavy resource requirements

Architecture

flowchart TB
    subgraph ControlPlane["Control Plane"]
        KS["Keystone\n(Identity & Auth)"]
        Glance["Glance\n(Image Service)"]
        Nova_API["Nova API\n(Compute)"]
        Neutron_API["Neutron\n(Networking)"]
        Cinder_API["Cinder\n(Block Storage)"]
        Heat["Heat\n(Orchestration)"]
        Horizon["Horizon\n(Web Dashboard)"]
    end

    subgraph Infra["Infrastructure Services"]
        MQ["RabbitMQ\n(Message Queue)"]
        DB["MariaDB / Galera\n(Database)"]
        Memcache["Memcached\n(Token cache)"]
    end

    subgraph Compute["Compute Nodes"]
        Nova_C["nova-compute\n(KVM / QEMU)"]
        OVN_A["OVN Agent\n(networking)"]
    end

    subgraph Storage["Storage"]
        Ceph["Ceph\n(block, object, file)"]
        Swift["Swift\n(Object Storage)"]
    end

    subgraph Network["Network Nodes"]
        OVN_C["OVN Controller\n(SDN)"]
        LB["Octavia\n(Load Balancer)"]
    end

    KS <--> MQ
    Nova_API <--> MQ <--> Nova_C
    Neutron_API <--> MQ <--> OVN_A
    Cinder_API <--> MQ
    All <--> DB
    Nova_C --> Ceph
    Cinder_API --> Ceph

    style ControlPlane fill:#ef3e42,color:#fff
    style Compute fill:#1565c0,color:#fff

Core Services

Service Project Role
Identity Keystone Authentication, authorization, service catalog
Compute Nova VM lifecycle, scheduling, live migration
Networking Neutron SDN, OVN, BGP, security groups, floating IPs
Block Storage Cinder Persistent volumes, snapshots, encryption
Object Storage Swift S3-compatible object store
Image Glance VM image registry and distribution
Dashboard Horizon Web GUI for operators and tenants
Orchestration Heat Stack-based resource orchestration (CFN-compatible)
Load Balancer Octavia LBaaS (amphora, OVN)
Bare Metal Ironic Physical server provisioning
DNS Designate DNSaaS
Container Magnum K8s cluster lifecycle on OpenStack

2026.1 "Gazpacho" Highlights

Feature Detail
Parallel live migration Multiple memory transfer connections simultaneously
Live migration with vTPM No cold restart for security-sensitive VMs
OVN BGP support Native BGP for external connectivity
Default IOThread Per-QEMU instance for disk I/O offloading
Async volume attach Decouple storage ops from API response
Ironic improvements Auto NFS/CIFS detection, trait-based port scheduling
SLURP release Direct upgrade from 2025.1 "Epoxy"

Pricing

Offering Cost
Self-hosted Free (Apache 2.0)
Canonical/MAAS Support subscriptions
Red Hat OpenStack Platform Enterprise subscription
SUSE Cloud Enterprise subscription
Managed (Rackspace, Vexxhost) Per-resource pricing

Compatibility

Dimension Support
Hypervisors KVM (primary), QEMU, Xen, VMware vCenter, Hyper-V, Ironic (bare metal)
Storage Ceph (block/object/file), LVM, NFS, iSCSI, FC, NetApp, Pure Storage
Networking OVN (default), OVS, Linux Bridge, SR-IOV, Mellanox
OS Ubuntu, RHEL, CentOS Stream, Rocky, Debian, SUSE
CPU architecture amd64, arm64, ppc64le, s390x

Sources