Chapter 1. Overview

1.1. Major changes in RHEL 8.8

Installer and image creation

Key highlights for image builder:

Image builder on-prem now offers a new and improved way to create blueprints and images in the image builder web console.
The RHEL for Edge Simplified Installer image type is now available in the image builder web console.

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

RHEL for Edge

RHEL for Edge introduces the following new feature in RHEL 8.8:

Specifying a user in a blueprint for simplified-installer images is now supported.

For more information, see New features - RHEL for Edge.

Security

Key security-related highlights:

The FIPS mode settings in the kernel have been adjusted to conform to the Federal Information Processing Standard (FIPS) 140-3. This change introduces stricter settings to many cryptographic algorithms, functions, and cipher suites.
The Libreswan IPsec implementation was rebased to version 4.9.
With the fapolicyd software framework, you can now filter the RPM database.
The OpenSCAP security compliance utility was rebased to version 1.3.7.
Rsyslog TLS-encrypted logging now supports multiple CA files.
The systemd-socket-proxyd service now runs in its own SELinux domain due to an update to the SELinux policy.

See New features - Security for more information.

Dynamic programming languages, web and database servers

Later versions of the following Application Streams are now available:

Python 3.11
nginx 1.22
PostgreSQL 15

The following components have been upgraded:

Git to version 2.39.1
Git LFS to version 3.2.0

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 8.8:

Valgrind 3.19
SystemTap 4.8
elfutils 0.188

Updated performance monitoring tools

The following performance monitoring tools have been updated in RHEL 8.8:

PCP 5.3.7
Grafana 7.5.15

Updated compiler toolsets

The following compiler toolsets have been updated in RHEL 8.8:

GCC Toolset 12
LLVM Toolset 15.0.7
Rust Toolset 1.66
Go Toolset 1.19.4

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

Java implementations in RHEL 8

The RHEL 8 AppStream repository includes:

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 8.8 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.

The web console

The RHEL web console now performs additional steps for binding LUKS-encrypted root volumes to NBDE deployments.

You can also apply the following cryptographic subpolicies through the graphical interface now: DEFAULT:SHA1, LEGACY:AD-SUPPORT, and FIPS:OSPP.

See New features - The web console for more information.

Containers

Notable changes include:

The podman RHEL System Role is now available.
Clients for sigstore signatures with Fulcio and Rekor are now available.
Skopeo now supports generating sigstore key pairs.
Podman now supports events for auditing.
The Container Tools packages have been updated.
The Aardvark and Netavark networks stack now supports custom DNS server selection.
Toolbox is now available.
Podman Quadlet is now available as a Technology Preview.
The container-tools:3.0 module stream has been deprecated.
The CNI network stack has been deprecated.

See New features - Containers for more information.

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 and RHEL 8.8 on the 64-bit Intel, IBM POWER 8 (little endian), and IBM Z architectures
From RHEL 7.6 to RHEL 8.4 on architectures that require kernel version 4.14: IBM POWER 9 (little endian) and IBM Z (Structure A). This is the final in-place upgrade path for these 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.

If you are upgrading to RHEL 8.8 with SAP HANA, ensure that the system is certified for SAP prior to the upgrade. 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.

Note

For the successful in-place upgrade of RHEL 7.6 for IBM POWER 9 (little endian) and IBM Z (structure A) architectures, you must manually download the specific Leapp data. For more information, see the Leapp data snapshots for an in-place upgrade Knowledgebase article.

Notable enhancements include:

The RHEL in-place upgrade path strategy has changed. For more information, see Supported in-place upgrade paths for Red Hat Enterprise Linux.
The latest release of the leapp-upgrade-el7toel8 package now contains all required data files. Customers no longer need to manually download these data files.
In-place upgrades using an ISO image that contains the target version are now possible.
RPM signatures are now automatically checked during the in-place upgrade. To disable the automatic check, use the --nogpgcheck option when performing the upgrade.
Systems that are subscribed to RHSM are now automatically registered with Red Hat Insights. To disable the automatic registration, set the LEAPP_NO_INSIGHTS_REGISTER environment variable to 1.
Red Hat now collects upgrade-related data, such as the upgrade start and end times and whether the upgrade was successful, for utility usage analysis. To disable data collection, set the LEAPP_NO_RHSM_FACTS environment variable to 1.

In-place upgrade from RHEL 6 to RHEL 8

To upgrade from RHEL 6.10 to RHEL 8, follow instructions in Upgrading from RHEL 6 to RHEL 8.

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 CentOS Linux 8 or Oracle 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.