This topic describes the lifecycle of an operating system and the characteristics of each phase. This topic also describes the security risks and challenges that an operating system may encounter after the operating system reaches end of life (EOL).
Phases of the operating system lifecycle
After an operating system is released, the operating system goes through the following key lifecycle phases based on the support of the operating system vendor:
Mainstream Support (MS) phase: The operating system vendor provides comprehensive support and services for the operating system, including updates, bug fixes, and technical support. In most cases, this phase lasts for an extended period of time until the operating system is no longer available for purchase.
Extended Life Support (ELS) phase: The availability of this phase depends on the operating system and market demand. In this phase, the operating system vendor provides limited support. In most cases, the support is limited to critical security updates and bug fixes. The vendor no longer provides new feature updates. In most cases, you are charged for the support in the ELS phase. Support may be available only to specific customers.
EOL phase: After an operating system reaches EOL, the operating system vendor no longer provides support for the operating system, including security updates and technical support. This means that the operating system is retired.
Driven by technological development and changes in market demand
The operating system lifecycle is driven by technological development and changes in market demand. As technologies develop, outdated operating systems may be unable to take full advantage of the latest hardware resources. Security threats are also evolving, which increases risks for outdated versions of operating systems. Vendors prefer investing resources in developing more advanced products because continuing to support outdated versions is costly and inefficient. Market demand also drives vendors to update operating systems. Outdated versions of operating systems cannot meet the growing requirements of users for new features, performance, and security. You can upgrade your operating system to the latest version at the earliest opportunity based on the timelines of the operating system lifecycle to ensure high performance and security.
Lifecycle status of mainstream operating systems
This section describes the lifecycle status of several mainstream operating systems.
CentOS
The CentOS community that released the CentOS operating systems announced that the CentOS Linux project was discontinued on December 8, 2020. On June 30, 2024, CentOS 7 entered the EOL phase. The CentOS community does not provide extended support for CentOS 7.
Version | Release date | Start date of the EOL phase |
CentOS 8 | 2019-09-24 | 2021-12-31 |
CentOS 7 | 2014-07-07 | 2024-06-30 |
CentOS 6 | 2011-11-27 | 2020-11-30 |
CentOS 5 | 2007-04-12 | 2017-03-31 |
Alibaba Cloud Linux
Alibaba Cloud Linux is a Linux operating system distribution developed by Alibaba Cloud. Alibaba Cloud continuously integrates developments from open source communities into Alibaba Cloud Linux to improve Linux features for applications in the cloud and uses a high-standard quality control system to ensure the quality of Alibaba Cloud Linux distributions. Alibaba Cloud Linux is also deeply optimized based on the Alibaba Cloud infrastructure and provides users with enterprise-level support and maintenance for up to 10 years. This improves the operating system experience for users.
Version | Release date | End date of the MS phase | End date of the ELS phase |
Alibaba Cloud Linux 3 | 2021-04-15 | 2031-04-30 | N/A |
Alibaba Cloud Linux 2 | 2019-03-27 | 2024-03-31 | 2026-03-31 |
Ubuntu
Ubuntu is an open source Linux operating system based on Debian. Ubuntu is designed to provide an easy-to-use and highly secure user experience on PCs, servers, and IoT devices. Ubuntu releases a Long Term Support (LTS) version every two years on average. Each LTS version has five years of mainstream support. After the MS phase of an LTS version ends, the version enters the ELS phase of up to seven years.
Version | Release date | End date of the MS phase | End date of the ELS phase |
Ubuntu 24.04 LTS | 2024-04 | 2029-04 | 2036 |
Ubuntu 22.04 LTS | 2022-04 | 2027-04 | 2034 |
Ubuntu 20.04 LTS | 2020-04 | 2025-04 | 2032 |
Ubuntu 18.04 LTS | 2018-04 | 2023-06 | 2030 |
Ubuntu 16.04 LTS | 2016-04 | 2021-04 | 2028 |
Ubuntu 14.04 LTS | 2014-04 | 2019-04 | 2026 |
Red Hat Enterprise Linux
Red Hat Enterprise Linux (RHEL) is an enterprise-level open source Linux operating system developed by Red Hat. RHEL provides high stability, security, and support services and is widely used on enterprise servers and in data center environments.
Version | Release date | MS phase | ELS phase end date | ||
Full Support end date | Maintenance Support 1 end date | Maintenance Support 2 end date | |||
Red Hat 9 | 2022-05-18 | 2027-05-31 | N/A | 2032-05-31 | 2035-05-31 |
Red Hat 8 | 2019-05-07 | 2024-05-31 | N/A | 2029-05-31 | 2032-05-31 |
Red Hat 7 | 2014-06-10 | 2019-08-06 | 2020-08-06 | 2024-06-30 | 2028-06-30 |
Red Hat 6 | 2010-11-10 | 2016-05-10 | 2017-05-10 | 2020-11-30 | 2024-06-30 |
Red Hat 5 | 2007-03-15 | 2013-01-08 | 2014-01-31 | 2017-03-31 | 2020-11-30 |
Red Hat 4 | 2005-02-14 | 2009-03-31 | 2011-02-16 | 2012-02-29 | 2017-03-31 |
Windows Server
Windows Server is a server operating system developed by Microsoft. Windows Server is widely used in enterprise-level environments and provides various features, such as network services, file storage, application hosting, security management, and virtualization, to support enterprise IT infrastructure and business applications.
Version | Release date | End date of the MS phase | End date of the ELS phase | End date of extended security updates |
Windows Server 2025 | 2024-11-01 | 2029-10-09 | 2034-10-10 | N/A |
Windows Server 2022 | 2021-08-18 | 2026-10-13 | 2031-10-14 | N/A |
Windows Server 2019 | 2018-11-13 | 2024-01-09 | 2029-01-09 | N/A |
Windows Server 2016 | 2016-10-15 | 2022-01-11 | 2027-01-12 | N/A |
Windows Server 2012 | 2012-10-30 | 2018-10-09 | 2023-10-10 | 2026-10-13 |
Windows Server 2008 | 2008-05-06 | 2015-01-13 | 2020-01-14 | 2023-01-10 |
Windows Server 2003 | 2003-05-28 | 2010-07-13 | 2015-07-14 | N/A |
For more information about the EOL timelines of Windows Server, visit the official Microsoft Windows Server website.
Other operating systems
Debian
Version | Code name | Release date | EOL date | EOL LTS | EOL ELTS |
Debian 13 | Trixie | To be decided | To be decided | To be decided | To be decided |
Debian 12 | Bookworm | 2023-06-10 | To be decided | To be decided | To be decided |
Debian 11 | Bullseye | 2021-08-14 | 2024-07 | To be decided | To be decided |
Debian 10 | Buster | 2019-07-06 | 2022-09-10 | 2024-06-30 | To be decided |
Debian 9 | Stretch | 2017-06-17 | 2020-07-18 | 2022-07-01 | 2027-06-30 |
Debian 8 | Jessie | 2015-04-25 | 2018-06-17 | 2020-06-30 | 2025-06-30 |
Debian 7 | Wheezy | 2013-05-04 | 2016-04-25 | 2018-05-31 | 2020-06-30 |
Debian 6.0 | Squeeze | 2011-02-06 | 2014-05-31 | 2016-02-29 | To be decided |
Debian 5.0 | Lenny | 2009-02-14 | 2012-02-06 | To be decided | To be decided |
For more information about the EOL, EOL LTS, and EOL Extended LTS (ELTS) phases of Debian, see Debian Releases.
Debian 9 and Debian 10 reached EOL. If you require specific installation packages in Debian 9 or Debian 10 during the transition period, change the repository addresses. For more information, see How do I change Debian 9 or Debian 10 repository addresses?
For more information about the EOL timelines of Debian, visit the official Debian website.
Anolis OS
Version | End-of-support date |
Anolis OS 8 | 2031-06-30 |
Anolis OS 7 | 2024-06-30 |
FreeBSD
Version | Release date | End-of-maintenance date |
FreeBSD 13.0 | 2021-04-13 | Three months after FreeBSD 13.1 release |
FreeBSD 12.3 | 2021-12-07 | Three months after FreeBSD 12.4 release |
FreeBSD 12.2 | 2020-10-27 | 2022-03-31 |
FreeBSD 12.1 | 2019-11-04 | 2021-01-31 |
FreeBSD 12.0 | 2018-12-11 | 2020-02-04 |
FreeBSD 11.4 | 2020-06-16 | 2021-09-30 |
FreeBSD 11.3 | 2019-07-09 | 2020-09-30 |
FreeBSD 11.2 | 2018-06-28 | 2019-10-31 |
FreeBSD 11.1 | 2017-07-26 | 2018-09-30 |
FreeBSD 11.0 | 2016-10-10 | 2017-11-30 |
For more information about the EOL timelines of FreeBSD, visit the official FreeBSD website.
openSUSE
Version | End-of-maintenance date |
openSUSE 15.3 | 2022-11-30 |
openSUSE 15.2 | 2022-01-04 |
openSUSE 15.1 | 2021-02-02 |
openSUSE 15.0 | 2019-12-03 |
openSUSE 42.3 | 2019-07-01 |
openSUSE 42.2 | 2018-01-26 |
openSUSE 42.1 | 2017-05-17 |
For more information about the EOL timelines of openSUSE, visit the official openSUSE website.
SUSE Linux
Version | Release date | End date of the General Support phase | End date of the ELS phase |
SUSE Linux Enterprise Server 15 SP6 | 2024-06-26 | Six months after SUSE Linux Enterprise Server 15 SP7 release | 42 months after SUSE Linux Enterprise Server 15 SP7 release |
SUSE Linux Enterprise Server 15 SP5 | 2023-06-20 | 2024-12-31 | 2027-12-31 |
SUSE Linux Enterprise Server 15 SP4 | 2022-06-21 | 2023-12-31 | 2026-12-31 |
SUSE Linux Enterprise Server 15 SP3 | 2021-06-22 | 2022-12-31 | 2025-12-31 |
SUSE Linux Enterprise Server 15 SP2 | 2020-07-21 | 2021-12-31 | 2024-12-31 |
SUSE Linux Enterprise Server 15 SP1 | 2019-06-24 | 2021-01-31 | 2024-01-31 |
SUSE Linux Enterprise Server 15 | 2018-07-16 | 2019-12-31 | 2022-12-31 |
SUSE Linux Enterprise Server 12 SP5 | 2019-12-09 | 2024-10-31 | 2027-10-31 |
SUSE Linux Enterprise Server 12 SP4 | 2018-12-12 | 2020-06-30 | 2023-06-30 |
SUSE Linux Enterprise Server 12 SP3 | 2017-09-07 | 2019-06-30 | 2022-06-30 |
SUSE Linux Enterprise Server 12 SP2 | 2016-11-08 | 2018-03-31 | 2021-03-31 |
SUSE Linux Enterprise Server 12 SP1 | 2015-12-15 | 2017-05-31 | 2020-05-31 |
SUSE Linux Enterprise Server 12 | 2014-10-27 | 2016-06-30 | 2019-07-01 |
For more information about the EOL timelines of SUSE Linux, visit the official SUSE Linux website.
Fedora
Version | End-of-maintenance date |
Fedora 40 | 2025-05-13 |
Fedora 39 | 2024-11-12 |
Fedora 38 | 2024-05-21 |
Fedora 37 | 2023-12-05 |
Fedora 36 | 2023-05-16 |
Fedora 35 | 2022-11-15 |
Fedora 34 | 2022-05-17 |
Fedora 33 | 2021-11-30 |
Fedora 32 | 2021-05-25 |
Fedora 31 | 2020-11-24 |
Fedora 30 | 2020-05-26 |
Fedora 29 | 2019-11-26 |
Fedora 28 | 2019-05-28 |
Fedora 27 | 2018-11-30 |
For more information about the EOL timelines of Fedora, visit the official Fedora website.
Rocky Linux
Version | Release date | End-of-maintenance date |
Rocky Linux 8 | 2021-05-01 | 2029-05-31 |
Rocky Linux 9 | 2022-07-14 | 2032-05-31 |
For more information about the EOL timelines of Rocky Linux, visit the official Rocky Linux website.
AlmaLinux
Version | Release date | End-of-maintenance date |
AlmaLinux 8.5 | 2021-11 | 2031-11 |
For more information about the EOL timelines of AlmaLinux, visit the official AlmaLinux website.
Fedora CoreOS
To be decided.
For information about the EOL timelines of Fedora CoreOS, visit the official Fedora CoreOS website.
Impacts of different operating system phases on business
MS phase
The vendor of an operating system provides comprehensive support and services for the operating system, including updates, bug fixes, and technical support. Take note of the bug patches released by the vendor and fix the bugs at the earliest opportunity to ensure business security and stability at the operating system layer.
Security and stability at the operating system layer are fundamental. You must also ensure security and reliability at the software architecture and business logic layers.
ELS phase
When an operating system is in the ELS phase, the operating system vendor provides limited security updates and technical support for the operating system. Compared with the MS phase, potential risks exist in the ELS phase.
Limited security updates: Compared with the MS phase, the number of security patches released in the ELS phase may be reduced and the release frequency may decrease. This reduces the protection capabilities of the operating system against the latest threats.
Stagnation of feature updates: In the ELS phase, new features are rarely developed for the operating system. Support in the ELS phase is limited to maintaining existing features and fixing major errors. You may be unable to obtain the latest technology and user experience improvements.
Increased costs: You may need to pay additional fees for additional support services, especially for commercial operating systems.
High migration pressure: Before the ELS phase ends, you may be pressured to migrate the original operating system to a new operating system. In most cases, the migration involves significant time and resource investments.
In summary, the ELS phase provides an extended period of time to mitigate the risks caused by the EOL phase. However, the risks are inevitable. One of the common methods used to mitigate the risks is to migrate the original operating system to the latest supported operating system version at the earliest opportunity. Strengthening existing security management measures can also alleviate the impacts of the end of official support.
EOL phase
After the operating system of an ECS instance reaches EOL, the operating system vendor no longer provides support for the operating system, including new software, new hardware, bug fixes, and security fixes. If you use an ECS instance whose operating system already reached EOL, the following issues may occur:
Security issues: The operating system no longer receives security updates or patches and becomes vulnerable to attacks and hacking. This may result in customer information leakage, system service interruptions, and ransomware attacks, which damage customer assets.
Compatibility issues: The operating system may be incompatible with new hardware and software, which causes the operating system to crash or fail to run as expected. This may increase the difficulties in upgrading the hardware or application software of customer service systems, which affects business development and competitiveness. Even if the operating system can run on new hardware, the operating system cannot utilize the full features of the hardware. For example, specific accelerators and acceleration instructions that can significantly improve performance can be adapted only to the latest operating systems and software. Running an EOL operating system on new hardware is not cost-effective.
Compliance issues: Using an EOL operating system may violate specific security and compliance standards of specific countries, regions, business sectors, and organizations. In this case, customers may face warnings from authorities or legal liabilities and fines and miss business opportunities.
Reliability issues: The operating system may encounter errors that result in system instability, data loss, or file corruption. This affects business operations and data integrity.
High maintenance costs: The operating system no longer receives technical support. Therefore, the time and costs to maintain and manage the operating system are high. The operating system may also encounter failures and downtime, which compromises business continuity. If issues can be resolved only by upgrading the operating system, you must make all necessary preparations before you perform the upgrade to avoid significant business risks.
References
For information about the EOL guidance for CentOS, see CentOS operating systems.
For information about the ELS guidance for Alibaba Cloud Linux 2, see Alibaba Cloud Linux operating systems.
For information about the ELS guidance for Ubuntu, see Ubuntu operating systems.
For information about the ELS guidance for RHEL 7, see Red Hat Enterprise Linux operating systems.
For information about the EOL guidance of Windows Server 2008 and Windows Server 2012, see Windows Server operating systems.