The Ubuntu lifecycle and release cadence

Canonical publishes new releases of Ubuntu on a regular cadence, enabling the community, businesses and developers to plan their roadmaps with the certainty of access to newer open source upstream capabilities.

Version numbers are YY.MM

Releases of Ubuntu get a development codename (‘GroovyGorilla’) and are versioned by the year and month of delivery - for example, Ubuntu 20.10 was released in October 2020.

Long term support and interim releases

LTS or ‘Long Term Support’ releases are published every two years in April. LTS releases are the ‘enterprise grade’ releases of Ubuntu and are utilised the most. An estimated 95% of all Ubuntu installations are LTS releases.

Every six months between LTS versions, Canonical publishes an interim release of Ubuntu, with 20.10 being the latest example. These are production-quality releases and are supported for 9 months, with sufficient time provided for users to update, but these releases do not receive the long-term commitment of LTS releases.

  Released End of Life Extended security maintenance
Ubuntu 10.04 LTS Apr 2010 Apr 2015  
Ubuntu 12.04 LTS Apr 2012 Apr 2017 Apr 2019
Ubuntu 14.04 LTS Apr 2014 Apr 2019 Apr 2022
Ubuntu 16.04 LTS Apr 2016 Apr 2021 Apr 2024
Ubuntu 18.04 LTS Apr 2018 Apr 2023 Apr 2028
Ubuntu 19.10 Oct 2019 Jul 2020  
Ubuntu 20.04 LTS Apr 2020 Apr 2025 Apr 2030
Ubuntu 20.10 Oct 2020 Jul 2021  
Ubuntu 21.10 Oct 2021 Jul 2022  
Ubuntu 21.04 Apr 2021 Jan 2022  
Ubuntu 22.04 LTS Apr 2022 Apr 2027 Apr 2032

Interim releases will introduce new capabilities from Canonical and upstream open source projects, they serve as a proving ground for these new capabilities. Many developers run interim releases because they provide newer compilers or access to newer kernels and newer libraries, and they are often used inside rapid devops processes like CI/CD pipelines where the lifespan of an artefact is likely to be less than the support period of the interim release. Interim releases receive full security maintenance for ‘main’ during their lifespan.

Release components - debs, snaps, images, containers

A release of Ubuntu is made through several different channels. What you consume will depend on where you are and what your interests happen to be.

The heart of Ubuntu is a collection of ‘deb’ packages which are tested and integrated so that they work well as a set. Debs are optimised for highly structured dependency management, enabling you to combine debs very richly while ensuring that the necessary software dependencies for each deb (themselves delivered as debs) are installed on your machine.

Ubuntu also supports ‘snap’ packages which are more suited for third-party applications and tools which evolve at their own speed, independently of Ubuntu. If you want to install a high-profile app like Skype or a toolchain like the latest version of Golang, you probably want the snap because it will give you fresher versions and more control of the specific major versions you want to track.

Snaps each pick a ‘base’, for example, Ubuntu18 (corresponding to the set of minimal debs in Ubuntu 18.04 LTS). Nevertheless, the choice of base does not impact on your ability to use a snap on any of the supported Linux distributions or versions — it’s a choice of the publisher and should be invisible to you as a user or developer.

A snap can be strictly confined, which means that it operates in a secure box with only predefined points of access to the rest of the system. For third-party applications, this means that you will have a very high level of confidence that the app can only see appropriate data that you have provided to it. Snaps can also be ‘classic’ which means that they behave more like debs, and can see everything on your system. You should make sure you have a high level of confidence in the publisher of any classic snap you install since a compromise or bad faith behaviour in that code is not confined to the app itself.

It is also common to consume Ubuntu as an image on a public cloud, or as a container. Ubuntu is published by Canonical on all major public clouds, and the latest image for each LTS version will always include security updates rolled up to at most two weeks ago. You may benefit from installing newer updates than that, but the base image you boot on the cloud should always be the current one from Canonical to ensure that it is broadly up to date and the number of updates needed for full security is minimal.

Canonical also publishes a set of images and containers that you can download for use with VMware or other local hypervisors and private cloud technologies. These include standard Ubuntu images on the Docker Hub and standard images for use with LXD and MAAS. These images are also kept up to date, with the publication of rolled up security updated images on a regular cadence, and you should automate your use of the latest images to ensure consistent security coverage for your users.

Editions, Classic and Core

Each release of Ubuntu is available in minimal configurations which have the fewest possible packages installed: available in the installer for Server, Desktop and as separate cloud images. There are also multiple flavours of desktop Ubuntu corresponding to a number of desktop GUI preferences. All of these images are considered ‘Classic’ Ubuntu because they use debs as their base and may add snaps for specific packages or applications.

The Ubuntu Core image is an all-snap edition of Ubuntu. It is unusual in that the base operating system itself is delivered as a snap; that makes it suitable for embedded appliances where all the possible apps that might need to be installed are available as strictly confined snaps. Ubuntu Core is an appliance or embedded oriented edition of Ubuntu, not particularly comfortable for humans but highly reliable and secure for large-scale appliance deployments such as IoT and CPE in the telco world.

Maintenance and security updates

The debs in Ubuntu are categorised by whether they are considered part of the base system (‘main’ and ‘restricted’ are in the base and ‘universe’ and ‘multiverse’ are not) and whether they are open source (‘main’ and ‘universe’ are, ‘restricted’ and ‘multiverse’ are not).

  Base Packages Extended Packages
Open Source main universe
Not Open Source restricted multiverse

The base system receives a commitment to public maintenance for the period where it is the current LTS or interim release and for a period thereafter.

Customers of Canonical often ask for an extended security maintenance commitment, either to ‘main’ for a longer period of time, or to ‘universe’ software packages during the initial maintenance period of the LTS. This is known as 'Extended Security Maintenance' or ESM and is available for LTS releases since Ubuntu 12.04 LTS.

LTS security maintenance 5-year initial period Up to an additional 5 years
main public ESM
universe Contact us Contact us

Ubuntu LTS releases transition into Extended Security Maintenance (ESM) phase as the standard, five-year public support window comes to a close. It is recommended for users and organisations to upgrade to the latest LTS release or subscribe to ESM for continued security coverage.

To check the support status of your system:

On Ubuntu 20.04 LTS, use this command:

For earlier versions of Ubuntu, use this command:

The Ubuntu Releases wiki has current information on previous and upcoming versions.

Ubuntu kernel release cycle

Canonical maintains multiple kernel packages for each LTS version of Ubuntu, which serve different purposes. Several of the kernel packages address the need for kernels with specific performance priorities, for example, the low-latency kernel package. Others are focused on optimisation for a particular hypervisor, for example, the kernel packages which are named after public clouds. You are recommended to use the detailed Ubuntu kernel guide to select the best Ubuntu kernel for your application.

In general, all of the LTS kernel packages will use the same base version of the Linux kernel, for example, Ubuntu 18.04 LTS kernels typically used the 4.15 upstream Linux kernel as a base. Some cloud-specific kernels may use a newer version in order to benefit from improved mechanisms in performance or security that are material to that cloud. These kernels are all supported for the full life of their underlying LTS release.

In addition, the kernel versions from the subsequent four releases are made available on the latest LTS release of Ubuntu. So Ubuntu 16.04 LTS received the kernels from Ubuntu 16.10, 17.04, 17.10 and 18.04 LTS. These kernels use newer upstream versions and as a result, offer an easy path to newer features and newer classes of hardware for many users of Ubuntu. Note however that these kernels ‘roll’ which means that they jump every six months until the next LTS. Large scale deployments that adopt the ‘hardware enablement’ or HWE kernels should manage those transitions explicitly. These newer HWE kernels are accompanied by a collection of userspace tools closely tied to the kernel and hardware, specifically X display enablement on newer graphics cards.

The Ubuntu kernel support lifecycle is as follows:

Release Released End of life Extended security maintenance
Ubuntu 18.04.5 LTS Aug 2020 Apr 2023 Apr 2028
Ubuntu 20.04 LTS Apr 2020 Apr 2025 Apr 2030
Ubuntu 18.04.4 LTS Feb 2020 Aug 2020  
Ubuntu 19.10 (v5.3) Oct 2019 Jul 2020  
Ubuntu 18.04.3 LTS (v5.0) Aug 2019 Feb 2020  
Ubuntu 19.04 (v5.0) Apr 2019 Jan 2020  
Ubuntu 18.04.2 LTS (v4.18) Feb 2019 Aug 2019  
Ubuntu 18.10 (v4.18) Oct 2018 Jul 2019  
Ubuntu 18.04.1 LTS (v4.15) Jul 2018 Apr 2023 Apr 2028
Ubuntu 16.04.5 LTS (v4.15) Aug 2018 Apr 2021 Apr 2024
Ubuntu 18.04.0 LTS (v4.15) Apr 2018 Apr 2023 Apr 2028
Ubuntu 16.04.1 LTS (v4.4) Aug 2016 Apr 2021 Apr 2024
Ubuntu 14.04.5 LTS (v3.13) Aug 2016 Apr 2019 Apr 2022
Ubuntu 16.04.0 LTS (v4.4) Apr 2016 Apr 2021 Apr 2024
Ubuntu 14.04.1 LTS (v3.13) Aug 2014 Apr 2019 Apr 2022
Ubuntu 12.04.5 LTS (v3.13) Aug 2014 Apr 2017 Apr 2019
Ubuntu 14.04.0 LTS (v3.13) Apr 2014 Apr 2019 Apr 2022
Ubuntu 12.04.1 LTS (v3.2) Aug 2012 Apr 2017 Apr 2019
Ubuntu 12.04.0 LTS (v3.2) Apr 2012 Apr 2017 Apr 2019

For more information on previous and upcoming kernel releases please see the Ubuntu LTS Enablement Stack wiki page.

Ubuntu OpenStack release cycle

Canonical’s Cloud Archive allows users the ability to install newer releases of Ubuntu OpenStack on an Ubuntu server as they become available. A given LTS release of Ubuntu will have the current release of OpenStack packaged in its release archives. The next four releases of OpenStack will then be published in the Cloud Archive for that LTS.

That means that it is possible to upgrade OpenStack four times on the same Ubuntu LTS release base operating system (upgrading the OpenStack without upgrading the operating system), and then one has the same OpenStack version that is included with the subsequent LTS release, and can choose to upgrade the operating system without upgrading the OpenStack version.

The middle OpenStack release (one year after the LTS release and one year before the next LTS release) is maintained for an extended period. Many customers therefore opt to make annual upgrades to their OpenStack rather than tracking each six-monthly release. The actual upgrade is fully supported using Canonical OpenStack tools and operator guides, and involves hopping through the six-monthly versions for database upgrade purposes, but the next effect is an annual upgrade to a version that is fully supportable.

The Ubuntu OpenStack support lifecycle can be represented this way:

Release Tech preview Released End of life Extended customer support Extended Security Maintenance (ESM)
OpenStack Y LTS   Apr 2022 Apr 2027   Apr 2032
Ubuntu 22.04 LTS   Apr 2022 Apr 2027   Apr 2032
OpenStack Y   Apr 2022 Apr 2025    
OpenStack X   Oct 2021 Apr 2023    
OpenStack W   Apr 2021 Oct 2022 Apr 2024  
OpenStack Victoria   Oct 2020 Apr 2022    
OpenStack Ussuri LTS Apr 2020 May 2020 Apr 2025   Apr 2030
Ubuntu 20.04 LTS   Apr 2020 Apr 2025   Apr 2030
OpenStack Ussuri Apr 2020 May 2020 Apr 2023    
OpenStack Train   Aug 2019 Feb 2021    
OpenStack Stein   Apr 2019 Oct 2020 Apr 2022  
OpenStack Rocky   Aug 2018 Feb 2020    
OpenStack Queens LTS   Apr 2018 Apr 2023   Apr 2028
Ubuntu 18.04 LTS   Apr 2018 Apr 2023   Apr 2028
OpenStack Queens   Feb 2018 Apr 2021    
OpenStack Mitaka LTS   Apr 2016 Apr 2021   Apr 2024
Ubuntu 16.04 LTS   Apr 2016 Apr 2021   Apr 2024

For more information on previous and upcoming Ubuntu OpenStack releases please see the Ubuntu Cloud Archive wiki page.

Charmed Kubernetes® release cycle

The release cycle of the Charmed Kubernetes is tightly synchronised to the release of upstream Kubernetes®. The current release and two prior releases are supported, giving an effective support period of nine months, subject to changes in the upstream release cycle.

The Charmed Kubernetes support lifecycle can be represented this way:

Release Released End of life
Kubernetes 1.19 Aug 2020 Jun 2021
Kubernetes 1.18 Mar 2020 Feb 2021
Kubernetes 1.17 Jan 2020 Dec 2020
Kubernetes 1.16 Oct 2019 Jul 2020
Kubernetes 1.16 Sep 2019 Jun 2020
Kubernetes 1.15 Jun 2019 Mar 2020
Kubernetes 1.14 Mar 2019 Dec 2019

For more information on previous and current releases of Charmed Kubernetes, please see the Charmed Kubernetes release notes.