Red Hat Enterprise Linux 8 Show
Instructions for an in-place upgrade from Red Hat Enterprise Linux 6 to Red Hat Enterprise Linux 8Abstract This document provides instructions on how to perform an in-place upgrade from Red Hat Enterprise Linux (RHEL) 6 to RHEL 8. Upgrading to RHEL 8 is a two-stage process. First you have to upgrade your system from RHEL 6 to RHEL 7 followed by an upgrade to RHEL 8. PrefaceThe guidelines in this document frequently refer to the following existing documentation:
This document also includes additional instructions specific to upgrading from RHEL 6 to RHEL 8. Making open source more inclusiveRed Hat is committed to replacing problematic language in our code, documentation, and web properties. We are beginning with these four terms: master, slave, blacklist, and whitelist. Because of the enormity of this endeavor, these changes will be implemented gradually over several upcoming releases. For more details, see our CTO Chris Wright’s message. Providing feedback on Red Hat documentationWe appreciate your feedback on our documentation. Let us know how we can improve it. Submitting comments on specific passages
Submitting feedback through Bugzilla (account required)
Key migration terminologyWhile the following migration terms are commonly used in the software industry, these definitions are specific to Red Hat Enterprise Linux (RHEL). Update Sometimes called a software patch, an update is an addition to the current version of the application, operating system, or software that you are running. A software update addresses any issues or bugs to provide a better experience of working with the technology. In RHEL, an update relates to a minor release, for example, updating from RHEL 8.1 to 8.2. Upgrade An upgrade is when you replace the application, operating system, or software that you are currently running with a newer version. Typically, you first back up your data according to instructions from Red Hat. When you upgrade RHEL, you have two options:
Operating system conversion A conversion is when you convert your operating system from a different Linux distribution to Red Hat Enterprise Linux. Typically, you first back up your data according to instructions from Red Hat. Migration Typically, a migration indicates a change of platform: software or hardware. Moving from Windows to Linux is a migration. Moving a user from one laptop to another or a company from one server to another is a migration. However, most migrations also involve upgrades, and sometimes the terms are used interchangeably.
Chapter 1. Planning an upgradeAn in-place upgrade is the recommended way to upgrade your system to a later major version of RHEL. Before you start, Red Hat recommends that you read this reference, including the linked documents, to prevent a situation when certain changes to your system have been done but you are unable to proceed with the upgrading process. Especially, ensure that your system meets the requirements described in this document and that you are aware of the known limitations. 1.1. RequirementsThe following are the general criteria a system must meet to upgrade from RHEL 6 to RHEL 8:
Note that there can be further requirements and limitations. For details, see:
1.2. ConsiderationsYou should consider the following before upgrading:
1.3. Overview of the upgrading processAn in-place upgrade from RHEL 6 to RHEL 8 requires the following major steps:
For detailed instructions, see the following chapters. :_content-type: PROCEDURE Chapter 2. Preparing a RHEL 6 system for an upgrade to RHEL 7This section provides an overview of steps necessary to prepare a RHEL 6 system for an upgrade to RHEL 7. To prepare your RHEL 6 system for an in-place upgrade to RHEL 7, perform the following steps:
Chapter 3. Upgrading from RHEL 6.10 to RHEL 7.9This section describes the key steps for an in-place upgrade from RHEL 6 to RHEL 7. The in-place upgrade consists of two major stages, a pre-upgrade assessment of the system, and the actual in-place upgrade:
To perform an in-place upgrade from RHEL 6 to RHEL 7:
Chapter 4. Preparing the RHEL 7 system for an upgrade to RHEL 8This section describes actions you need to perform on your RHEL 7 system before you can proceed with the upgrade to RHEL 8. To prepare your RHEL 7 system for the upgrade to RHEL8, follow these steps:
Chapter 5. Upgrading from RHEL 7.9 to RHEL 8This section describes how to update a RHEL 7 host to RHEL 8. Note that RHEL version 7.9 is a prerequisite for upgrading to RHEL 8. Similarly to the in-place upgrade from RHEL 6 to RHEL 7, the in-place upgrade consists of two major stages, a pre-upgrade assessment of the system in which the system remains unchanged, and the actual in-place upgrade. In case of a RHEL 7 to RHEL 8 upgrade, both phases are handled by the Leapp utility. To perform an in-place upgrade from RHEL 7.9 to RHEL 8:
Additional resources
Chapter 6. Performing post-upgrade tasksThis section suggests major actions you should take after upgrading the system to RHEL 8. After you have upgraded your system to RHEL 8, complete especially the following tasks:
Chapter 7. TroubleshootingThis section describes how to troubleshoot and solve package-related issues after the in-place upgrade from both RHEL 6 to RHEL 7 and RHEL 7 to RHEL 8. 7.1. Ensuring that installed packages match the current major RHEL versionEnsure that only packages are installed that have been built for the currently installed major RHEL version:
7.2. Fixing dependency errorsAfter an in-place upgrade, it is possible that packages are installed while some of their dependencies have been removed by the upgrade tool. To solve this problem:
7.3. Installing missing packages after upgrading to RHEL 7If you miss certain packages after the upgrade from RHEL 6 to RHEL 7, you probably did not provide a repository to the Red Hat Upgrade Tool that contained these packages. To install these packages after the upgrade, you can use, for example, the following commands: # cd /root/preupgrade # bash noauto_postupgrade.d/install_rpmlist.sh kickstart/RHRHEL7rpmlist_kept Note that
different issues can prevent installing the RPMs. In this case, resolve the problems. For further details about other files with lists of packages you should install on the upgraded system, see the 7.4. Known issuesFor known issues when upgrading:
7.5. Additional resources
Legal NoticeCopyright © 2022 Red Hat, Inc. The text of and illustrations in this document are licensed by Red Hat under a Creative Commons Attribution–Share Alike 3.0 Unported license ("CC-BY-SA"). An explanation of CC-BY-SA is available at http://creativecommons.org/licenses/by-sa/3.0/. In accordance with CC-BY-SA, if you distribute this document or an adaptation of it, you must provide the URL for the original version. Red Hat, as the licensor of this document, waives the right to enforce, and agrees not to assert, Section 4d of CC-BY-SA to the fullest extent permitted by applicable law. Red Hat, Red Hat Enterprise Linux, the Shadowman logo, the Red Hat logo, JBoss, OpenShift, Fedora, the Infinity logo, and RHCE are trademarks of Red Hat, Inc., registered in the United States and other countries. Linux® is the registered trademark of Linus Torvalds in the United States and other countries. Java® is a registered trademark of Oracle and/or its affiliates. XFS® is a trademark of Silicon Graphics International Corp. or its subsidiaries in the United States and/or other countries. MySQL® is a registered trademark of MySQL AB in the United States, the European Union and other countries. Node.js® is an official trademark of Joyent. Red Hat is not formally related to or endorsed by the official Joyent Node.js open source or commercial project. The OpenStack® Word Mark and OpenStack logo are either registered trademarks/service marks or trademarks/service marks of the OpenStack Foundation, in the United States and other countries and are used with the OpenStack Foundation's permission. We are not affiliated with, endorsed or sponsored by the OpenStack Foundation, or the OpenStack community. All other trademarks are the property of their respective owners. |