What's New in Red Hat Enterprise Linux 9

First major release since IBM spent $ 34 billion to purchase the giant distro, includes 5.14 kernels, systemd 249, Python 3.9 and more

Red Hat has officially unveiled version 9 of Red Hat Enterprise Linux (RHEL), codenamed Plow, the latest major version of the dominant commercial Linux pay server.

This version aims to implement features and functionality without being too different from its big brothers. The IBM subsidiary said it expected the platform to become generally available in the "next few weeks".

Version 9 marks a number of firsts. It's the first major release since IBM's acquisition of Red Hat closed in July 2019; RHEL 8.0 came out two months earlier. It's also the first major release of the enterprise distribution since Red Hat rebranded its free CentOS enterprise distribution as a RHEL upstream rather than a rebuild.

At Managedserver.it, we reviewed the beta last year. This release is based on Fedora 34, which we discussed in March of last year. This means several significant changes for desktop users, including GNOME 40, which should run on Wayland by default, the Pipewire audio server, and incremental updates to Flatpak packages.

The release uses kernel 5.14, systemd 249, Python 3.9, PHP 8, and GCC 11.2. It includes a web console based on the Cockpit project , which now supports live patching of the running kernel using the kpatch tool . There is also a container management toolbox, based on the upstream toolbx project.

As we noted when examining the packaging of Linux apps last year, Flatpak remains a primarily desktop-centric format, unlike Ubuntu's Snap format which, in our opinion, targets both the desktop and the server. Since most RHEL 9 deployments will likely be on servers, containers will be more meaningful for app deployment. The new version presents changes significant to container management, including cgroupsversion 2 and the use of crundefault container runtime.

Get access to the latest runtimes and tools

• Red Hat Enterprise Linux 9 is built with a set of runtimes and compilers latest, including GCC 11.2.1 and updated versions of LLVM (13.0.1), Rust (1.58.1) and Go (1.17.1), allowing developers to modernize their applications.
• RHEL 9 comes with updated versions of major developer toolchains such as GCC (11.2.1), glibc (2.34), and binutils (2.35). New features in the GCC compiler help users better monitor code flow, improve debugging options, and write optimized code for efficient hardware use. The new GCC compiler includes changes for compiling the code C and C ++ , along with new debug messages for the logs. This gives developers better performance management of their code.
• With application flows Next generation, developers will have more choices when it comes to versions of popular languages ​​and tools. Red Hat Enterprise Linux 9 enhances the application flow experience by providing initial versions of the application flow that can be installed as RPM packages using the yumtraditional installation command. Developers can choose from multiple versions of user space components as easy-to-upgrade application streams, giving them greater flexibility to customize RHEL for their development environment. The content of the application flow also includes tools and applications that move very fast and are updated frequently. These application flows, called rotating flows, are fully supported for the life of RHEL 9.
• Red Hat Enterprise Linux 9 extends the module packaging capabilities of RHEL 8. With RHEL 9, all packaging methods, such as Red Hat Software Collections , Flatpak and traditional RPMs have been incorporated into application flows, making it easier for developers to use their favorite packages.

Support for the latest language runtime versions

• Python 3.9 gets lifetime support in Red Hat Enterprise Linux 9 and comes with a host of new features, including time zone timestamps, new string prefix and suffix methods, dictionary merge operations, high performance parser , multiprocessing improvements and more. These features will help developers easily modernize their applications.
• Node.js  16 provides changes that include an update of the V8 engine to version 9.2, a new Timer Promises API, a new experimental API for web streams, and support for npm Package Manager version 7.20.3. Node.js is now compatible with OpenSSL 3.0.
• Ruby 3.0.3 provides several performance improvements, along with bug and security fixes. Some of the notable improvements include concurrency and parallelism, static analysis, matching patterns with case/ inexpressions, redesigned one-line pattern matching, and search pattern matching.
• Perl 5.32 provides a number of bug fixes and enhancements, including Unicode version 13, a new experimental fixture operator, faster feature checks, and more.
• PHP 8.0 provides several bug fixes and improvements, such as the use of structured metadata syntax, new order-independent arguments, improved performance for Just-In-Time compilation, and more.

Create Red Hat Enterprise Linux images for development and testing

Image Builder is a tool that allows users to create custom RHEL system images in a variety of formats for major and minor releases. These images are compatible with major cloud providers and the most popular virtualization technologies on the market. This allows users to quickly create custom RHEL development environments on local, on-premise, or cloud platforms.

With Image Builder, custom filesystem configurations can be specified in blueprints to create images with a specific disk layout, instead of using the default layout configuration.

Image Builder can be used to create bootable ISO installation images. These images consist of a tarball that contains a root filesystem that you can use to install directly on a bare metal server, which is ideal for popping up test hardware for edge developments.

Monitor and maintain Red Hat Enterprise Linux environments

The Red Hat Enterprise Linux 9 web console features an advanced performance metrics page that helps identify potential causes of high CPU, memory, disk, and network resource usage spikes. Furthermore, the subsystem metrics can be easily exported to a Grafana server.

RHEL 9 now also supports live kernel patching via the web console. The latest critical security kernel patches and updates can be applied immediately without the need for scheduled downtime and without interrupting ongoing development or production applications.

Build containers with Universal Base Images

Red Hat Enterprise Linux 9 ships with control groups (cgroups) and a recent version of Podman with improved default settings. Container signature and short name validation is enabled by default and containerized applications can be tested on the default RHEL 9 configuration.

RHEL 9 UBI is available in standard, micro, minimal, or init image configurations, ranging in size from as little as 7,5 MB to 80 MB. Learn more about building, running, and managing containers.

Identity and security

• With Red Hat Enterprise Linux 9, authentication of the root user with a password over SSH has been disabled by default. The default OpenSSH configuration does not allow root user access with a password, thus preventing attackers from gaining access via password brute force attacks. Instead of using the root password, developers can log into remote development environments using SSH keys to log in.
• OpenSSL 3.0 adds a provider concept, a new version control scheme, and an improved HTTPS. Providers are collections of algorithm implementations. Developers can programmatically invoke any provider based on application requirements. The built-in RHEL utilities have been recompiled to use OpenSSL 3. This allows users to leverage new security codes to encrypt and protect information.

RHEL is a relatively slow, technologically conservative distribution. As with any long-term supported distribution, this can cause problems when newer versions of core components are needed.

Red Hat's solution to this problem is what it calls Application Streams , which allows you to install specific versions of operating system components along with their various dependencies. These receive more frequent updates than the underlying core operating system, although this can mean shorter support lifespans.

Pricing starts at $179 for the workstation edition , if you can live without support, and $299 with one year of support. The most basic server edition starts at $349 without support, $799 with one year of standard support (business hours), and $1.299 for premium support (24×7) for severity 1 and 2 cases.

RHEL 9 can also be downloaded for free as part of the Red Hat Developer Program membership. In this article, you'll learn some of the ways RHEL 9 can improve the developer experience.

Assuming Red Hat follows the existing lifecycle , RHEL 9.0 will receive full support for the next five years, until mid-2027, followed by another five years of “maintenance” support, meaning no new features and limited additional support for new hardware.

However, as we have already explained for version 7 and version 8 of the distribution of the same name and related forks such as RockyLinux or AlmaLinux, it will most likely be possible to use tools such as elevate to upgrade the current RHEL 9 to a probable and future RHEL 10.