CentOS

Overview

CentOS (Community Enterprise Operating System) is a free, open source Linux distribution, originally designed as a community-supported platform that is fully functionally compatible with Red Hat Enterprise Linux (RHEL). It is built by recompiling the RHEL source code to provide enterprise-level stability and reliability. CentOS has two main branches:

• CentOS Linux: The traditional version, directly based on RHEL, focuses on long-term stability, and is suitable for enterprise servers, but all updates will be stopped on June 30, 2024 (CentOS Linux 7 ends support, and CentOS Linux 8 has been terminated in December 2021).

• CentOS Stream: It has become the main direction of CentOS since 2020, positioned as the "midstream" development platform of RHEL, between Fedora (upstream) and RHEL (downstream), using rolling updates, providing features that are about to enter RHEL, suitable for developers and RHEL ecosystem contributors.

CentOS uses the RPM package manager and YUM/DNF tools, and supports x86-64, ARM64, and POWER8 architectures (CentOS 7 and earlier versions support IA-32). It is widely used in enterprise servers, cloud computing, virtualization, and containerization environments, especially in scenarios where RHEL compatibility is required.

History and Development

• Origin:
  • CentOS began in 2002 and originated from CAOS Linux (an RPM distribution created by Gregory Kurtzer). In May 2004, CentOS 2 was released, based on RHEL 2.1AS, becoming a free alternative to RHEL.
  • In 2006, Tao Linux (another RHEL clone) was merged into CentOS to expand the community.
  • In January 2014, Red Hat announced its sponsorship of the CentOS project and the establishment of the CentOS Management Committee to maintain community independence.
• Development History:
  • 2004-2019:
    • CentOS 2 (2004) to CentOS 7 (2014) are directly based on RHEL and are widely used in enterprise servers. In 2010, it surpassed Debian to become the most popular Linux web server distribution.
    • CentOS 8 was released on September 24, 2019, based on RHEL 8.2.
  • 2020-2021:
    • In December 2020, Red Hat announced the termination of CentOS Linux development. CentOS 8 support will end in advance on December 31, 2021, and CentOS 7 support will end on June 30, 2024, switching to CentOS Stream.
    • CentOS Stream is positioned as a development platform for RHEL and uses rolling updates.
    • In 2021, the community was dissatisfied with Red Hat's decision, resulting in AlmaLinux (initiated by CloudLinux) and Rocky Linux (initiated by Gregory Kurtzer) as the successors of CentOS Linux.
  • 2024-2025:
    • CentOS Stream 9 (released in 2021) and CentOS Stream 10 (December 2024) continue to develop and support the latest RHEL features, such as Linux kernel 6.6 and PostgreSQL 16.
    • CentOS Linux 7 and 8 stop updating, and users need to migrate to CentOS Stream, AlmaLinux or Rocky Linux.
    • Post X said that "CentOS Stream 10's rolling updates are suitable for developers, but enterprise users prefer Rocky Linux."
• Community and Support:
  • Maintained by the CentOS project and the Red Hat community, hosted on centos.org and GitHub.
  • Provides CentOS Wiki (wiki.centos.org), mailing lists, and X communities (such as @CentOS).
• Open Source License:
  • Adopts licenses such as GPL v2 (core components), MIT, etc.

Main Features

CentOS (especially CentOS Stream) is known for its enterprise-level stability, RHEL compatibility, and development flexibility. The following are its main features:

1. RHEL compatibility
   • CentOS Stream provides the same RPM package management and ecosystem as RHEL, supporting enterprise-level software.
2. Rolling Update (CentOS Stream)
   • Provides features that are coming to RHEL, such as Python 3.12, PostgreSQL 16.
3. Enterprise-level support
   • Supports SELinux (Security Enhanced Linux), Podman (container management), and KVM (virtualization).
4. Software Ecosystem
   • Software Collections (SCL):
     • Provides new versions of software (such as Python 3.12) without interfering with the system default version.
5. Desktop and Server
   • Desktop Support:
     • Supports desktop environments such as GNOME, Xfce, etc.

Advantages and Limitations

Advantages

• RHEL Compatibility:
  • 100% compatible with RHEL, suitable for enterprise-level medical applications.
  • X post says "CentOS Stream is the perfect test platform for RHEL development"
• Rolling Update:
  • CentOS Stream provides the latest features.
• Enterprise-level stability:
  • SELinux and Podman enhance security.
• Extensive ecosystem:
  • Supports RPM packages, SCL and Podman.
• Community support:
  • Support is provided by Red Hat and the community (such as AlmaLinux, Rocky Linux).

Limitations

• CentOS Linux end of life:
  • CentOS Linux 7 and 8 have stopped supporting, users need to migrate to CentOS Stream, AlmaLinux or Rocky Linux.
  • Solution: Use CentOS Stream or AlmaLinux.
• Rolling update is unstable:
  • Rolling updates of CentOS Stream may introduce instability.
  • Solution: Use AlmaLinux or Rocky Linux in production environments.
• Learning curve:
  • SELinux and DNF configuration is complex.
  • Solution: Refer to wiki.centos.org.
• Limited desktop support:
  • No graphical interface by default, manual configuration is required.
  • Solution: Install Xfce or GNOME.

Summary

CentOS is a free, open source Linux distribution, originally based on RHEL, providing enterprise-level stability. It is now mainly based on CentOS Stream, adopts rolling updates, and is positioned as a midstream development platform for RHEL. It uses RPM package management and DNF, supports x86-64, ARM64 and POWER8 architectures, and is suitable for servers, containers and virtualization. CentOS Stream is suitable for enterprise-level development and RHEL ecology.