Chapter 1. Overview

Installer and image creation

Key highlights for RHEL image builder:

For more information, see New features - Installer and image creation.

Security

The system-wide cryptographic policies introduce the PQ subpolicy to enable post-quantum cryptography (PQC) algorithms and contain many improvements to support PQC in applications.

OpenSSL 3.5 introduces support for the ML-KEM, ML-DSA, and SLH-DSA post-quantum algorithms and adds the hybrid ML-KEM algorithms to the default TLS group list.

See New features - Security for more information.

Kernel

RHEL 9.7 adds kernel-area improvements that advance performance analysis and energy telemetry. Updates include a refined jitter entropy source in rng-tools, upstream alignment for perf and BPF to v6.14 and v6.15, expanded uncore and core event counters, Intel RAPL energy events, Intel Trace Hub (NPK) device IDs, and refreshed crash analysis and python-drgn tooling. NVMe‑TCP kdump to an NVMe namespace can fail in some environments. Apply operational caution where this limitation is relevant.

Dynamic programming languages, web and database servers

Later versions of the following Application Streams are now available:

See New features - Dynamic programming languages, web and database servers and Technology Previews - Dynamic programming languages, web and database servers for more information.

Compilers and development tools

Updated system toolchain

The following system toolchain components have been updated:

Updated performance tools and debuggers

The following performance tools and debuggers have been updated in RHEL 9.7:

Updated performance monitoring tools

The following performance monitoring tools have been updated in RHEL 9.7:

.NET 10.0 is now available on RHEL

Red Hat Enterprise Linux (RHEL) supports .NET, a general-purpose development platform that features automatic memory management and modern programming languages, allowing you to build high-quality applications efficiently. This update adds support for the most recent version, .NET 10.0 (Long-Term Support), expanding the versions available on RHEL. Other supported versions include .NET 9.0 (Standard-Term Support) and the previous long-term support version, .NET 8.0.

For more information, see Release Notes for .NET 10.0 RPM packages and Release Notes for .NET 10.0 containers

Updated compiler toolsets

The following compiler toolsets have been updated in RHEL 9.7:

For detailed changes, see New features - Compilers and development tools.

The web console

The cockpit packages have been upgraded to version 344, which provides many improvements, most notably the upgrade to the Patternfly 6 system design.

See New features - The web console for more information.

In-place upgrade from RHEL 8 to RHEL 9

The supported in-place upgrade paths currently are:

For more information, see Supported in-place upgrade paths for Red Hat Enterprise Linux.

For instructions on performing an in-place upgrade, see Upgrading from RHEL 8 to RHEL 9.

For instructions on performing an in-place upgrade on systems with SAP environments, see How to in-place upgrade SAP environments from RHEL 8 to RHEL 9.

Notable enhancements and bug fixes include:

In-place upgrade from RHEL 7 to RHEL 9

It is not possible to perform an in-place upgrade directly from RHEL 7 to RHEL 9. However, you can perform an in-place upgrade from RHEL 7 to RHEL 8 and then perform a second in-place upgrade to RHEL 9. For more information, see In-place upgrades over multiple RHEL major versions by using Leapp.

Red Hat Customer Portal Labs is a set of tools in a section of the Customer Portal available at https://access.redhat.com/labs/. The applications in Red Hat Customer Portal Labs can help you improve performance, quickly troubleshoot issues, identify security problems, and quickly deploy and configure complex applications. Some of the most popular applications are:

Capabilities and limits of Red Hat Enterprise Linux 9 as compared to other versions of the system are available in the Knowledgebase article Red Hat Enterprise Linux technology capabilities and limits.

Information regarding the Red Hat Enterprise Linux life cycle is provided in the Red Hat Enterprise Linux Life Cycle document.

The Package manifest document provides a package listing for RHEL 9, including licenses and application compatibility levels.

Application compatibility levels are explained in the Red Hat Enterprise Linux 9: Application Compatibility Guide document.

Major differences between RHEL 8 and RHEL 9, including removed functionality, are documented in Considerations in adopting RHEL 9.

Instructions on how to perform an in-place upgrade from RHEL 8 to RHEL 9 are provided by the document Upgrading from RHEL 8 to RHEL 9.

Red Hat Insights is now Red Hat Lightspeed. This is a change in name only and all the same product features, functionalities, and capabilities you have relied on under the Red Hat Insights name remain under the name Red Hat Lightspeed. With Red Hat Lightspeed, which is included with all RHEL subscriptions, you can proactively identify, examine, and resolve known technical issues. For instructions on how to install the client and register your system to the service, see the Red Hat Lightspeed documentation page.