The basis for the new version 8.2.2004 of the free Linux distribution CentOS Linux is Red Hat Enterprise Linux 8.2, which was released at the end of April 2020.
CentOS 2/8/2004 is ready: Within less than 50 days, the development team created the latest version of the free replica from the source code packages of the commercial Red Hat Enterprise Linux (RHEL) 8.2. After the first CentOS of the 8 version series was released more than four months after Red Hat Enterprise Linux of the same version, the time between RHEL and CentOS releases has leveled off at around two months.
As always, the freely available Linux distribution behaves like Red Hat Enterprise Linux and is binary-compatible with it. The release notes for CentOS 8.2.2004 therefore simply refer to those of RHEL 8.2 with regard to the new features.
Differences to RHEL
However, it is not a completely identical clone. Differences are not only evident in the design – the trademarked graphics from IBM/Red Hat are always missing in the CentOS packages – but also in the range of functions. Features such as live patching for running systems without a restart (Kpatch), which require a paid Red Hat subscription, are missing. Also, the optional security policies for CentOS are simply copies of those policy sets from Red Hat Enterprise Linux 8.2, without certification by the CentOS project.
But there are also differences in the update policy: In case With the last CentOS version, updates in the last phase before the next version was completed were sometimes missing for up to several weeks. In this context, the CentOS developers refer to the possibility of activating the optional continuous release repository in order to receive updates earlier. After some basic tests, this repository delivers new packages faster than the regular sources.
In addition, since September 2019 there has also been an edition of the distribution, CentOS Stream, which behaves like a rolling release. With the subsequent installation of the package “centos-release-stream” Administrators can also turn a CentOS 8.2 into CentOS Stream and then draw from generally newer package sources. The price is another step away from the RHEL code.
Containers under control
The main innovations in CentOS 8.2 are product maintenance. The 4.18 kernel used now has full support for the second version of the control groups (cgroups v2), which are used to allocate system resources such as memory and computing time to processes. Control groups are essential for systemd process management, container runtimes such as LXC and Docker, but also for virtualizing guest systems using Libvirt.
Because some prominent container tools such as Docker and Kubernetes do not support cgroups v2, this feature remains deactivated for the time being and is still waiting to be activated with the kernel boot parameter “systemd.unified_cgroup_hierarchy=1”.
The new tool “Udica” is also about controlling containers: It is used to analyze container processes in order to create customized SELinux guidelines for them as additional protection.
For hard-working servers with high I/O loads, the Logical Volume Manager 2 (LVM2) offers the Possibility to add a cache on a fast SSD to slow hard drives. This can now be set up specifically as a write cache. New drivers are included for the GPU of Intel’s Ice Lake CPU as well as for the Nvidia chips of the TU116 family and for AMD Navi 10.
Further highlights can be found in the form of a brief overview in the release notes from RHEL 8.2.
Update and available ISO files
An already installed CentOS 8.1911 can be easily updated with the package manager “dnf” update to the latest version. However, a bug report on the new CentOS version indicates that a distribution update will initially be available without the “microcode” should take place to avoid system hangs.
CentOS version 8 will continue to receive updates until May 2029.Apart from the x86 platform (64-bit), there is CentOS for 64-bit ARM (aarch64) and for IBM’s PowerPC platform (ppc64el).
CentOS 2/8/2004 is available on the download servers available in three variants: as an ISO file with all packages and more than 7 GB in size, as an installer in DVD size and as a minimal network installer that installs all packages via an Internet connection.