Release Policy
1 July 2025
OpenNebula provides this Release Cycle Policy in order for customers and partners to effectively plan, deploy, and support their infrastructure. OpenNebula publishes this Policy in an effort to provide as much transparency as possible, but please be aware that we might have to make exceptions to these plans should circumstances so require.
OpenNebula follows a rapid release cycle to improve user satisfaction by rapidly delivering new features and innovations based on their requirements and feedback. In other words, giving our users and customers what they need more quickly, in smaller increments, while regularly increasing the product’s overall technical quality. At the same time, for those looking for a slower, more steady pace of change, without intermittent minor enhancements, OpenNebula provides long-term support (LTS) releases.
OpenNebula publishes major, minor and maintenance releases:
- Each major release of OpenNebula is denoted by a single major number (i.e. OpenNebula 7). A new major release typically comes with significant additions that may involve changes in the interfaces, core or database, and so may require a complex upgrade process for production environments.
- Each minor release of OpenNebula is denoted by a major and a minor number (i.e. OpenNebula 7.2). A new minor release typically involves enhancements, optimizations and bug fixes that may bring along small changes to the core and database, and so allow a seamless update process for production environments following a pre-defined migration path.
- Maintenance releases of OpenNebula are denoted by a major, a minor and an incremental number (i.e. OpenNebula 7.0.1). A maintenance release typically includes only bug fixes and minor enhancements, and its upgrade is straightforward. Major and minor releases are defined as “main releases”. Exceptionally, the project may deliver patch releases (i.e. OpenNebula 7.0.0.1) with critical bug fixes.
Four weeks before an official major or minor release date, there is a beta release series. This beta series marks the feature-freeze for the release. Development efforts are then mainly devoted to bug fixing and polishing. A release candidate version is usually published one week before an official major or minor release date.
We aim to produce:
- A new major release approximately every 3 to 5 years.
- Between 6 and 10 minor releases for each major version, issued approximately every 6 months.
- At least one maintenance release every 3 months, providing bug fixes, security updates, and incremental improvements.
While there is a single OpenNebula software distribution, some releases—primarily major and minor versions—are made available as Community Editions, while others—mainly maintenance releases—are distributed exclusively to organizations with an active Enterprise Subscription (referred to as Enterprise Editions). For example, while version 6.10 was released publicly as a Community Edition, all subsequent maintenance releases in the 6.10.x series (from 6.10.1 to 6.10.4) were made available exclusively to customers with an active Enterprise Subscription.
Therefore, OpenNebula releases can belong to either of the following two software editions:
- Community Edition (CE): A fully featured, publicly available version of OpenNebula. It provides all core functionalities of the platform, making it suitable for development, testing, and community-driven environments.
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Enterprise Edition (EE): A more thoroughly tested, hardened, and production-ready release of OpenNebula, designed specifically for enterprise use. It includes:
- Additional bug fixes and software patches beyond the Community Edition.
- Minor new features and optimizations developed by OpenNebula Systems.
- Specialized, enterprise-grade drivers and integrations for key infrastructure platforms — for example, backup solutions such as Veeam, and storage systems like NetApp.
The Enterprise Edition ensures higher stability, performance, and support for mission-critical production environments.
The Community Editions of OpenNebula and their associated binary packages are distributed under the Apache License, Version 2.0. These correspond to the major and minor releases of OpenNebula, which are updated and published every six months and maintained through the OpenNebula Community Forum. As a general rule, the OpenNebula Project does not publish public maintenance releases; only patch releases addressing critical bug fixes are issued—for example, OpenNebula 5.12.0.1.
One of the key benefits of the OpenNebula Enterprise Subscription is access to Expanded Maintenance, which provides several enterprise-grade advantages—including access to maintenance versions of OpenNebula and the implementation of an STS/LTS release model designed to deliver long-term software maintenance and stability for production environments.
The OpenNebula versions released under the Enterprise Edition, representing the production-ready builds of OpenNebula, are distributed under a commercial license governed by the OpenNebula Subscription Agreement. The maintenance versions of OpenNebula are updated and released every three months and are maintained through the Customer Portal for Corporate Users with an active OpenNebula Subscription. Customers also gain access to exclusive Enterprise Tools that simplify upgrades, lifecycle management, and the maintenance of OpenNebula clouds in production environments, as well as Enterprise Drivers that provide enhanced integration with commercial infrastructure technologies.
LTS (Long-Term Support) releases are issued every two years and are considered the enterprise-grade releases recommended for most production deployments. Each LTS release receives three years of standard maintenance for all packages in the repository. Additionally, the Extended Life Add-on can extend the lifetime of an LTS release from three years up to four and a half years, ensuring maximum platform continuity.
Between LTS releases, OpenNebula provides STS (Short-Term Support) versions, which are interim production-quality releases issued every six months. Three STS releases are typically provided between two consecutive LTS versions. Each STS release is commercially supported for nine months, allowing sufficient time for users to upgrade to newer versions, while not offering the same long-term commitment as LTS releases.
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An STS version are maintained and technically supported for a period of 9 months. This incorporates the 6 months until the next main version (LTS or STS) is available, plus 3 additional months thereafter. These are production-quality releases that serve as a proving ground for new capabilities by customers interested in adopting new major features and are able to perform upgrades multiple times a year.
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An LTS version are maintained and technically supported for a period of at least 36 months. This incorporates the time until the next LTS is available (which is at least for 24 months, but could be for longer), plus an additional 12 months thereafter. LTS releases are the “enterprise grade” releases of OpenNebula and are intended to be utilized primarily in production environments by customers interested in a release family with an extended support cycle. There is also a support extension for Extended Life Support.
From its 7th month, the releases enter into “Maintenance Support” in which they will receive only critical and compatible fixes throughout their lifecycle, (no additional minor enhancements). And the last 6 months of an LTS release support overlaps with the beginning of “Maintenance Support” for the subsequent LTS release. This provides a simple way for customers who are averse to too many changes to remain in the maintenance and extended support phases with no minor features across two LTS releases.
The lifetime of each main (major/minor) release may include the following phases:
- Mainstream Support (STS/LTS), regular maintenance versions with bug fixing and minor enhancements, and enterprise support.
- Maintenance Support (LTS only), regular maintenance versions with bug fixing, and enterprise support.
- Extended Support (STS/LTS), critical bug fixing and enterprise support. During this phase, customers are expected to upgrade to the next release.
Each OpenNebula major or minor version is initially released as a Community Edition, and after approximately three months, a corresponding maintenance release is issued exclusively for Enterprise deployments. Community users typically need to wait until the next major or minor release (approximately every six months) to receive the accumulated bug fixes, patches, and minor enhancements that were developed and incorporated into the Enterprise Edition during the previous maintenance cycle.
OpenNebula Community serves as a proving ground for new capabilities. Many companies run these releases because they provide newer features, and they are often used inside rapid devops processes like CI/CD pipelines where the lifespan of an artifact is likely to be less than the support period of each release.
Our software is thoroughly tested through an internal Quality Assurance process before its release. Although our Community Edition is a full-featured version of OpenNebula, the Enterprise Edition provides a more tested, hardened, and production-ready version of OpenNebula that incorporates additional bug fixes developed by OpenNebula Systems and software patches with minor enhancements (except for LTS versions), along with a series of Enterprise Tools and Drivers to simplify upgrades and the maintenance of OpenNebula clouds in production environments.
Once the QA process is completed, we prepare packages of all releases for the most common Linux distributions. Only those created for the Community Edition are made public. Packages for the Enterprise Edition are private and only available through the Customer Portal. During the entire life cycle, we make reasonable efforts to maintain compatibility for the core and database across all minor and maintenance releases, but sometimes we have to make exceptions to this general compatibility goal due to critical impact or other significant issues.
Users of OpenNebula Community Edition can obtain support from fellow users through our Community Forum. Corporate Users with an active OpenNebula Subscription have access not only to the Enterprise Edition and its private maintenance releases, but also to exclusive Enterprise Tools and technical contents, SLA-based support and Professional Services via the Customer Portal.