- Red Hat Enterprise Linux 4
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- How to upgrade from one Major version of the Red Hat Enterprise Linux OS to another?
- Installation media does not include an upgrade option
Upgrade to Red Hat Enterprise Linux 4, 5, 6
Red Hat does not support in-place upgrades between major versions 4, 5 and 6 of Red Hat Enterprise Linux. (A major version is denoted by a whole number version change. For example, Red Hat Enterprise Linux 5 and Red Hat Enterprise Linux 6 are both major versions of Red Hat Enterprise Linux).
In-place upgrades across major releases do not preserve all system settings, services or custom configurations. Consequently, Red Hat strongly recommends fresh installations when upgrading from one major version to another. After a fresh installation alongside an existing server installed with Red Hat Enterprise Linux , you can migrate your settings, software and data to the new server in order to ensure they are all successful and all of your software runs as expected. This also helps to ensure that your data is safely transported from backup to the new system for your fresh start.
- Having said this, there is an upgrade option that can be used at your own risk to allow an upgrade without requiring a full reinstall. To get this functionality, insert the installation CD of the new version and enter the following command at the boot prompt:
# linux upgradeany
This will walk you through the upgrade procedure, which very closely resembles a normal installation. Again, the process noted above is not supported by Red Hat and should not be used in production environments. After this upgrade procedure, should you call into Red Hat for support, Red Hat will support the resulting system as if it were a clean installation only. Any issues not related to the upgrade will be supported. If at any time a problem appears to be the result of an in-place upgrade procedure, Red Hat may require you to reinstall the system.
- Red Hat recommends that you do a complete backup of your system before you attempt the upgrade.
- If there were any third party packages involved in the previous installation, re-install them.
- Individual package configuration files may or may not work after performing an upgrade due to changes in various configuration file formats or layouts.
- If any of Red Hat's layered products (such as the Cluster Suite) were installed, it may need to be manually upgraded after the OS upgrade has been completed. Some layered products, like CloudForms, do not support the underlying OS to be upgraded due to the significant changes between RHEL6 and RHEL7 packages (like databases) upon which the layered product relies.
- The upgrade option is known to cause erratic system behavior in some cases.
- In cases where unexpected results occur, Red Hat Global Support Services may have no choice but to walk you through a reinstallation and recommended migrations.
As per document link, Red Hat Enterprise Linux 6 Installation Guide, Chapter 37. Upgrading Your Current System
Once upgraded or re-installed, re-register system as described at
* How do I re-register my system with Red Hat Network (RHN) Classic ?
* How to register and subscribe a system to the Red Hat Customer Portal using RHSM
Upgrade to Red Hat Enterprise Linux 7
Red Hat currently supports only upgrades from Red Hat Enterprise Linux 6 to Red Hat Enterprise Linux 7 for specific/targeted use cases only. More information can be found at the following links:
- How do I upgrade from RHEL 6 to RHEL 7?
- How do I subscribe to the RHEL Extras channel/repo?
- Red Hat Enterprise Linux 7 Installation Guide
Upgrade to Red Hat Enterprise Linux 8
- How do I upgrade from Red Hat Enterprise Linux 7 to Red Hat Enterprise Linux 8?
- Considerations in adopting RHEL 8
- Upgrading from RHEL 6 to RHEL 8
- Upgrading from RHEL 7 to RHEL 8
Upgrade to Red Hat Enterprise Linux 9
- Upgrading from RHEL 8 to RHEL 9 Red Hat Enterprise Linux 9
- Considerations in adopting RHEL 9 Red Hat Enterprise Linux 9
- Red Hat Enterprise Linux
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