Chapter 1. Overview

1.1. Major changes in RHEL 8.9

Installer and image creation

Key highlights for image builder:

Enhancement to the AWS EC2 AMD or Intel 64-bit architecture AMI image to support UEFI boot, in addition to the legacy BIOS boot.

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

Security

Key security-related highlights:

OpenSCAP was rebased to version 1.3.8.
ANSSI-BP-028 SCAP security profiles were updated to version 2.0.
SCAP Security Guide now contains improved rules to provide more consistent interactive user configuration and the DISA STIG profile supports audit_rules_login_events_faillock.

See New features - Security for more information.

Dynamic programming languages, web and database servers

Node.js 20 is now available as a new module stream.

See New Features - Dynamic programming languages, web and database servers for more information.

Compilers and development tools

Updated performance tools and debuggers

The following performance tools and debuggers have been updated in RHEL 8.9:

Valgrind 3.21
SystemTap 4.9
elfutils 0.189

Updated performance monitoring tools

The following performance monitoring tools have been updated in RHEL 8.9:

Grafana 9.2.10
grafana-pcp 5.1.1

Updated compiler toolsets

The following compiler toolsets have been updated in RHEL 8.9:

GCC Toolset 13 (new)
LLVM Toolset 16.0.6
Rust Toolset 1.71.1
Go Toolset 1.20.10

See New features - Compilers and development tools for more information.

Java implementations in RHEL 8

The RHEL 8 AppStream repository includes:

The java-21-openjdk packages, which provide the OpenJDK 21 Java Runtime Environment and the OpenJDK 21 Java Software Development Kit.
The java-17-openjdk packages, which provide the OpenJDK 17 Java Runtime Environment and the OpenJDK 17 Java Software Development Kit.
The java-11-openjdk packages, which provide the OpenJDK 11 Java Runtime Environment and the OpenJDK 11 Java Software Development Kit.
The java-1.8.0-openjdk packages, which provide the OpenJDK 8 Java Runtime Environment and the OpenJDK 8 Java Software Development Kit.

The Red Hat build of OpenJDK packages share a single set of binaries between its portable Linux releases, RHEL 8.9 and later releases. Because of this update, there is a change in the process of rebuilding the OpenJDK packages on RHEL from the source RPM. For more information about the new rebuilding process, see the README.md file which is available in the SRPM package of the Red Hat build of OpenJDK and is also installed by the java-*-openjdk-headless packages under the /usr/share/doc tree.

For more information, see OpenJDK documentation.

1.2. In-place upgrade and OS conversion

In-place upgrade from RHEL 7 to RHEL 8

The possible in-place upgrade paths currently are:

From RHEL 7.9 to RHEL 8.6 RHEL 8.8 and RHEL 8.9 on the 64-bit Intel, IBM POWER 8 (little endian), and IBM Z architectures
From RHEL 7.9 to RHEL 8.6 and RHEL 8.8 on systems with SAP HANA on the 64-bit Intel architecture.

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 7 to RHEL 8.

For instructions on performing an in-place upgrade on systems with SAP environments, see How to in-place upgrade SAP environments from RHEL 7 to RHEL 8.

Notable enhancements include:

Requirements on disk space have been significantly reduced on systems with XFS filesystems formatted with ftype=0.
Disk images created during the upgrade process for upgrade purposes now have dynamic sizes. The LEAPP_OVL_SIZE environment variable is not needed anymore.
Issues with the calculation of the required free space on existing disk partitions have been fixed. The missing free disk space is now correctly detected before the required reboot of the system, and the report correctly displays file systems that do not have enough free space to proceed the upgrade RPM transaction.
Third-party drivers can now be managed during the in-place upgrade process using custom leapp actors.
An overview of the pre-upgrade and upgrade reports is now printed in the terminal.
Upgrades of RHEL Real Time and RHEL Real Time for Network Functions Virtualization (NFV) in Red Hat OpenStack Platform are now supported.

In-place upgrade from RHEL 6 to RHEL 8

It is not possible to perform an in-place upgrade directly from RHEL 6 to RHEL 8. However, you can perform an in-place upgrade from RHEL 6 to RHEL 7 and then perform a second in-place upgrade to RHEL 8. For more information, see Upgrading from RHEL 6 to RHEL 7.

In-place upgrade from RHEL 8 to RHEL 9

Instructions on how to perform an in-place upgrade from RHEL 8 to RHEL 9 using the Leapp utility are provided by the document Upgrading from RHEL 8 to RHEL 9. Major differences between RHEL 8 and RHEL 9 are documented in Considerations in adopting RHEL 9.

Conversion from a different Linux distribution to RHEL

If you are using Alma Linux 8, CentOS Linux 8, Oracle Linux 8, or Rocky Linux 8, you can convert your operating system to RHEL 8 using the Red Hat-supported Convert2RHEL utility. For more information, see Converting from an RPM-based Linux distribution to RHEL.

If you are using an earlier version of CentOS Linux or Oracle Linux, namely versions 6 or 7, you can convert your operating system to RHEL and then perform an in-place upgrade to RHEL 8. Note that CentOS Linux 6 and Oracle Linux 6 conversions use the unsupported Convert2RHEL utility. For more information on unsupported conversions, see How to perform an unsupported conversion from a RHEL-derived Linux distribution to RHEL.

For information regarding how Red Hat supports conversions from other Linux distributions to RHEL, see the Convert2RHEL Support Policy document.

1.3. Red Hat Customer Portal Labs

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:

1.4. Additional resources

Capabilities and limits of Red Hat Enterprise Linux 8 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 8.
Major differences between RHEL 7 and RHEL 8, including removed functionality, are documented in Considerations in adopting RHEL 8.
Instructions on how to perform an in-place upgrade from RHEL 7 to RHEL 8 are provided by the document Upgrading from RHEL 7 to RHEL 8.
The Red Hat Insights service, which enables you to proactively identify, examine, and resolve known technical issues, is now available with all RHEL subscriptions. For instructions on how to install the Red Hat Insights client and register your system to the service, see the Red Hat Insights Get Started page.

Note

Release notes include links to access the original tracking tickets. Private tickets have no links and instead feature this footnote.^[1]