1.1. New features of Centos8
This section mainly explains the new features of CentOS8. Compared with the previous version of CentOS8, what new features have been updated?
CentOS8 was finally released on September 24, 2019. Since this is a Linux distribution derived from Red Hat Enterprise Linux (RHEL), CentOS fully complies with Red Hat's redistribution policy and is fully functionally compatible with upstream products. The main changes of CentOS 8 are consistent with RedHat Enterprise Linux 8 (referred to as RHEL 8, Chinese name Red Hat Enterprise Linux 8). Based on Fedora 28 and kernel version 4.18, CentOS's modification of components is mainly to remove the Red Hat trademark and artwork.
The CentOS system is widely used by developers and system administrators because it provides complete control over its highly customizable open source software packages. It is stable, with a large and active support community behind it. Due to its reliability, it has become the mainstream choice for server operating systems.
Let's take a look at all the new features and updates provided by CentOS8.
1. Using Linux kernel version 4.18, CentOS8 and RedHat8 have the same new features. Based on the kernel version of 4.18, it provides AMD and Intel 64-bit architecture, as well as 64-bit arm, IBM Power Systems, Little Endian, and IBM Z.
2. The software warehouse is updated, and the content is distributed in two main software warehouses: BaseOS repository and AppStream Repository.
BaseOS software warehouse: For the software warehouse, we have a Base source by default in the previous system. In CentOS8, the content in the BaseOS software warehouse is mainly an RPM package that provides the functions of the underlying operating system, providing a most basic The installation package, which is provided in RPM format.
AppStream software warehouse: AppStream is a new feature and a highlight of the new version. It mainly includes other user space applications, runtime languages, and databases. A simple understanding is the application of many third parties because of user space. Components are usually updated more frequently than operating system software packages, so it separates the two parts and introduces the concept of AppStream, mainly to provide more flexibility and stability at the bottom of the system.
Attachment: AppStream explains that
AppStream is a new extension to the traditional rpm format, providing multiple major versions for a component at the same time. Application streams are usually named according to the software version they distribute, such as mongodb: 3.4 or mongodb: 3.6, but you can also use " Names such as "stable" and "latest".
Reference materials:
https://wiki.centos.org/zh/FAQ/CentOS8
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/8.0_release_notes/distribution-of-content-in -rhel-8 # application_streams
3. The latest version control system is provided in the new version centos8, including:
Git 2.18, a distributed version control system with decentralized architecture.
Mercurial 4.8, a lightweight distributed version control system, designed for efficient processing of large projects.
Subversion 1.10, centralized version control system
4, web server, web tools, development language and database
Centos 8 includes multiple versions of database, development language and other tools available for your application, the following are available on centos 8 Component list:
python: The default Python in centos 8 is Python 3.6 version. This package may not be installed by default. To install Python 3.6, use the yum install python3 command, and continue to support python2.7, but only support Python 2.7 for a limited life cycle, and its purpose is to promote a smooth transition from users to Python3.
Nodejs: provides node.js 10, other dynamic language updates include: PHP 7.2, Ruby 2.5, Perl 5.26, SWIG 3.0.
centos 8 provides Apache 2.4.37, Nginx 1.14 (first introduced)
The database services provided by centos 8 include: MariaDB 10.3, MySQL 8.0, PostgreSQL 10, PostgreSQL 9.6, and Redis 5.
Squid version is upgraded to 4.4, and Varnish Cache 6.0 is also provided for the first time.
GCC compiler 8.1
glibc library based on version 2.28
, compiler and development tools
Gcc compiler updated to version 8.2, supports more C ++ standards, better optimization and code enhancement technology, promotion warnings and hardware feature support.
The glibc library is upgraded to 2.28.
Provide OpenJDK 11, OpenJDK 8, IcedTea-Web, and different Java tools, such as Ant, Maven, or Scala.
6. Software management
CentOS 8 comes with yum package manager v4.0.9 version, which now uses DNF (Dandified YUM) technology as the backend. DNF is a new generation of YUM. The new operating system version allows you to use both tools to manage packages.
The software management tool used by default in Centos 8 is changed from the original version of yum to a faster dnf. The original yum command is only a dnf soft link.
A new upgrade has also been made to the familiar yum package management. In the new version, the YUM package manager is based on DNF technology and integrated with DNF technology. The latest version has a greatly improved software management system. And supports modular content, enhanced performance, and provides a well-designed API for integration with other tools. Cloud application streaming, container workloads, and CI / CD.
The RPM version is 4.14.2, which verifies the contents of the entire package before starting the installation.
The YUM version provided in centos 8 is v4.0.9. Compared with the previous YUM v3 used on centos 7, YUM based on DNF has the following advantages:
1), improved performance
2), supports modular content
3), carefully designed and stable API, can be integrated with the tool. For
details, please refer to: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/8.0_release_notes/RHEL-8_0_0_release#software-management
7. The desktop environment
GNOME Shell is upgraded to 3.28 .
GNOME session and display management uses Wayland as the default display server, while RHEL 7's default X.Org server is still provided. 
8. Network
Use the network manager (nmcli and nmtui) for network configuration, remove the network script
nftables framework instead of iptables as the default network packet filtering tool
The firewalld daemon uses nftables as the default backend.
Supports IPVLAN virtual network driver, which can provide network connection for multiple containers.
9. File system and storage.
The maximum size of the XFS file system has been increased from 500 TiB to 1024 TiB.
LUKS version 2 (LUKS2) format replaces the old version of LUKS (LUKS1) format; use LUKS2 as the default format for encrypted volumes. LUKS2 provides metadata redundancy and automatic recovery for encrypted volumes in the event of partial metadata corruption.
For details, refer to: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/8.0_release_notes/RHEL-8_0_0_release#filesystems-storage
10, Cockpit WEB console
Open web-based console interface , Cockpit, is now part of the new CentOS release. Use this platform to easily manage the server through the web console interface. Perform system tasks, create and manage virtual machines, configure networks, start containers, and check logs through a web browser.
Cockpit is highly integrated. It not only has an embedded terminal, which allows you to switch from the terminal to the browser at any time, but also works on mobile devices.
Therefore, when you install CentOS 8, it will automatically set up the Cockpit web console and open the required firewall port. However, there is no need to worry about it will increase the burden on the system. The software is very effective because it only uses memory and CPU when active.
I will not introduce CentOS8 much. For details, please refer to the following link:
https://wiki.centos.org/en/Manuals/ReleaseNotes/CentOS8.1905
CentOS 8 official release notes
https://lists.centos.org/pipermail/centos-announce/2019-September/023449.html
Complete RedHat 8 For release notes, please see
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/8.0_release_notes/overview
1.2, Centos8 install
CentOS 8 Download:
domestic Alibaba Cloud mirror download:
http: // mirrors .aliyun.com / centos / 8.0.1905 / isos / x86_64 / CentOS-8-x86_64-1905-dvd1.iso
CentOS 8 official download: https://centos.org/download/
CentOS Linux DVD ISO: CentOS 8 stable Operating system, which system administrators can use to deploy or configure services and applications.
CentOS stream DVD ISO: A rolling Linux distribution, suitable for developers who need frequent updates.
Attachment: CentOS Streams
The CentOS 8 version also includes the new CentOS Streams. Centos Stream is a rolling Linux distribution. You can use CentOS Streams as a version to experience the latest Red Hat Linux features without having to wait too long.
The minimum hardware configuration required for CentOS 8:
◈ At least 2 GB memory, the official recommendation is a minimum of 2G memory, 4G memory or above is recommended
◈ 64-bit x86 architecture, 2 GHz or above CPU
◈ 20 GB hard disk space
CentOS8 installation is not too complicated , No difference from the previous version installation, it is recommended to minimize the installation. The specific installation process is omitted.