Switch from CentOS/Rocky Linux to Oracle Linux
This script is designed to automatically switch a CentOS or Rocky Linux instance to Oracle Linux by removing any distribution-specific packages or replacing them with the Oracle Linux equivalent.
Supported versions and architectures
This script currently supports switching CentOS Linux 6, CentOS Linux 7,
CentOS Linux 8, Rocky Linux 8 and Rocky Linux 9 on both x86_64
and aarch64
architectures.
It does not support CentOS Stream.
Support for switching Rocky Linux should be considered experimental due to limited testing. Likewise, switching any of the operating systems mentioned above on
aarch64
hosts should be considered experimental.The script does not support switching from Rocky Linux images built for Raspberry Pi (aarch64).
Please ensure you have a complete working backup before attempting to switch and report any issues you encounter during the process.
Before you start
IMPORTANT: this script is a work-in-progress and is not designed to handle all possible configurations. Please ensure you have a complete working backup of the system before you start this process in the event the script is unable to convert the system successfully or unable to rollback the changes it made.
NOTE: CentOS 8 has reached end-of-life and its repos have moved to vault.centos.org
.
Please ensure that your CentOS 8 system is up-to-date and able to access those
repos before you start.
Remove all non-standard kernels
Because of the GRUB2 BootHole vulnerability, our SecureBoot shim can
only boot kernels signed by Oracle and we can only replace the default
CentOS kernels. While this may not have an impact if SecureBoot is currently
disabled, enabling it at a later date could render the system unbootable.
For that reason, we strongly recommend removing all non-standard kernels, i.e.
any kernel that is installed that is not provided by either the base
or
updates
repo. This includes the centosplus
kernels.
- Ensure your CentOS
yum
ordnf
configuration is working, i.e. there are no stale repositories. - Disable all non-CentOS repositories. You can re-enable the repos after the switch.
- Ensure you have at least 5GB of free space in
/var/cache
. - All automatic updates, e.g. via
yum-cron
should be disabled.
Usage
- Login to your CentOS Linux 6, 7 or 8 or Rocky Linux 8 or 9 instance as a user
who has
sudo
privileges. - Either clone this repository or download the
centos2ol.sh
script. - Run
sudo bash centos2ol.sh
to switch your CentOS instance to Oracle Linux.
Usage options
-
-r
Reinstalls all CentOS RPMs with Oracle Linux RPMsIf a system is switched to Oracle Linux and there is no newer Oracle Linux version of a package already installed then the CentOS version remains. This option proceeds to reinstall any CentOS RPM with an identical version from Oracle Linux. This is not necessary for support and has no impact to a systems functionality but is offered so a user can remove CentOS GPG keys from the truststore. A list of all non-Oracle RPMs will be displayed after the reinstall process.
-
-k
Do not install the UEK kernel and disable UEK reposThis option will not install the UEK kernel and will disable all UEK yum repositories.
-
-V
Verify RPM information before and after the switchThis option creates four output files in
/var/tmp/
:${hostname}-rpms-list-[before|after].log
: a sorted list of installed packagesbefore
andafter
the switch to Oracle Linux.${hostname}-rpms-verified-[before|after].log
: the RPM verification results for all installed packagesbefore
andafter
the switch to Oracle Linux.
Testing
See TESTING.md
for instructions on the available tests and
how to run them.
Known issues
-
There is a reported issue with the upstream OpenJDK package resetting the
alternatives
configuration during adnf reinstall
transaction.We recommend recording the output of
alternatives --list
prior to runningcentos2ol.sh
and reviewing the same output after switching. If you experience an issue with a package other than OpenJDK, please open an issue
Limitations
- The script currently needs to be able communicate with the CentOS/Rocky and Oracle Linux yum repositories either directly or via a proxy.
- The script currently does not support instances that are registered to a third-party management tool like Spacewalk, Foreman or Uyuni.
- Compatibility with packages installed from third-party repositories is
expected but not guaranteed. Some software doesn't like the existence of an
/etc/oracle-release
file, for example. - Packages that install third-party and/or closed-source kernel modules, e.g. commercial anti-virus products, may not work after switching.
- The script only enables the base repositories required to enable switching to Oracle Linux. Users may need to enable additional repositories to obtain updates for packages already installed (see issue #1.
Debugging
Run sudo bash -x centos2ol.sh
to switch your CentOS instance to Oracle Linux
in debug mode. This will print a trace of commands and their arguments or
associated word lists after they are expanded but before they are executed.
Get involved
We welcome contributions! See our contribution guidelines.
Support
- Open a GitHub issue for non-security related bug reports, questions, or requests for enhancements.
- To report a security issue or vulnerability, please follow the reporting security vulnerabilities instructions.
Resources
For more information on Oracle Linux, please visit oracle.com/linux.
Contributing
This project welcomes contributions from the community. Before submitting a pull request, please review our contribution guide
Security
Please consult the security guide for our responsible security vulnerability disclosure process
License
Copyright (c) 2020, 2023 Oracle and/or its affiliates.
Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/