CentOS Linux 8 released. It is a Linux distro derived from RHEL 8. CentOS was created when Red Hat stopped providing RHEL free. These days CentOS mostly used on servers, HPC, and desktop. CentOS is a high-quality Linux distribution. It gives complete control of its open-source software packages and is fully customized for research needs or for running a high-performance website without the need for license fees. Let us see what’s new in CentOS 8.
What’s new in CentOS Linux 8?
Let us quickly look into CentOS Linux 8 features.
“BaseOS” and “AppStream”.
The principal repository, BaseOS, provides the parts of the distribution that give you running userspace on physical hardware, a virtual machine, a cloud instance, or a container. The Application Stream (AppStream) repository provides all the applications you might want to run in given userspace. The Supplemental repository provides other software that has special licensing.
CentOS 8 Linux runs on:
- x86_64 (64 bit Intel/AMD)
- aarch64 (64-bit ARM)
- ppc64le (IBM POWER, little endian)
You can manage CentOS 8 servers with Cockpit via a web browser. A handy feature for new users and experienced sysadmins alike.
New container tools
CentOS 8 support Linux Containers using Podman. It replaces Docker and Mobdy which run as root and depends upon daemons. The Podman act as daemonless. One can use Buildah to create containers images from scratch, or a Dockerfile.
In wayland the compositor is the display server. We transfer the control of KMS and evdev to the compositor. The wayland protocol lets the compositor send the input events directly to the clients and lets the client send the damage event directly to the compositor.
The CentOS 8 desktop with Wayland and X
Wayland is the default display server, but one can still use Xorg if needed. Wayland offers many benefits over the X display server such as dealing with bottleneck between clients and Linux kernel.
One can use the loginctl command to verify that Wayland being used on CentOS 8 desktop:
Systemwide crypto policies
One can use update-crypto-policies command to update or set up system-wide cryptographic policy on CentOS for TLS/SSH/Kerberos and so on:
The policies currently provide settings for these applications and libraries:
- BIND DNS name server daemon
- GnuTLS TLS library
- OpenJDK runtime environment
- Kerberos 5 library
- Libreswan IPsec and IKE protocol implementation
- NSS TLS library
- OpenSSH SSH2 protocol implementation
- OpenSSL TLS library
TCP stack improvements
CentOS Linux 8 comes with TCP stack version 4.16 which improves ingress connection rate. Linux kernel now support new BBR and NV congestion control algorithms. This is useful to increase your Linux server Internet speed with TCP BBR congestion control.
Say hello dnf
The yum command is now symbolically linked to dnf from Fedora project. It provides better software management. You can use yum or dnf to install, delete, update, and manage software packages on CentOS 8. In other words, CentOS 8 comes with yum version 4 that uses dnf technology as its back end. You get support for software AppStreams for cloud, CI/CD, and Linux container workloads. All commands are backward compatible so you can use yum without any issues. For example:
sudo yum check-updates sudo yum module list sudo yum upgrade python2 sudo yum module install postgresql:10
Important software and updates
Look Ma, newer and better software for development cool apps on CentOS Linux 8:
Other improvements and new features in CentOS 8 Linux
- CentOS 8 supports secure-boot guests or VMs which use cryptographically signed images to ensure integrity.
- You need to use the nmcli command to manage network configuration through NetworkManager.
- Improved memory management and support. For example, CentOS 8 provides support for for 57-bit virtual memory addressing (128 PiB ) and 52-bit physical memory addressing (up to 4 PiB
- RAM). Linux kernel supports a 5-level page table implementation.
- Crash dump can capture kernel crash during all phases of booting which was not possible on CentOS Linux 7
- The process scheduler made many enhancements. Also includes the new deadline process scheduler.
- Can install and boot from non-volatile dual in-line memory module (NVDIMM)
- nftables is a framework by the Netfilter Project that provides packet filtering, network address translation (NAT) and other packet manglin. It is the default firewall backend on CentOS 8.
- chrony is a versatile implementation of the Network Time Protocol (NTP). It can synchronise the system clock with NTP servers and is default on CentOS 8. Old ntpd is gone.
- LUKS2 for encrypted storage on CentOS 8
Where to download CentOS 8
Visit mirror here or click on the following url CentOS 8 ISO image:
CentOS 8 Stream DVD ISO:
What is CentOS Stream?
The CentOS Stream project sits between the Fedora Project and RHEL in the RHEL Development process, providing a “rolling preview” of future RHEL kernels and features. This enables developers to stay one or two steps ahead of what’s coming in RHEL, which was not previously possible with traditional CentOS releases. CentOS Stream better connects ISV, IHV and other ecosystem developers to the operating system developers of the Fedora Project, shortening the feedback loop and making it easier for all voices to be heard in the creation of the next RHEL versions.
Missing packages or apps from CentOS 8
- The Btrfs file system has been removed from CentOS 8
- KDE support removed
- Network scripts are deprecated
- See deprecated functionality and removed security functionality
How to upgrade to CentOS 8 from CentOS 7
You can upgrade CentOS 7 to CentOS 8, using the command line option.
CentOS 8 is a significant upgrade that ships with much-updated software that developers like to build web apps and container workload. The desktop provides a pleasant experience. In short, I highly recommend this version.