Chapter 5. Installer and image creation
This chapter lists the most notable changes to installer and image creation between RHEL 8 and RHEL 9.
Anaconda activates network automatically for interactive installations
Anaconda now activates the network automatically when performing interactive installation, without requiring users to manually activate it in the network spoke. This update does not change the installation experience for kickstart installations and installations using the
ip= boot option.
New options to
Lock root account and
enable password-based SSH root login
RHEL 9 adds following new options to the root password configuration screen:
Lock root account: To lock the root access to the machine
Allow root SSH login with password: To enable password-based SSH root logins.
During the kickstart installation method, enable the password-based SSH root logins by adding the following line to the kickstart file.
%post echo "PermitRootLogin yes" > /etc/ssh/sshd_config.d/01-permitrootlogin.conf %end
Licensing, system, and user setting configuration screens have been disabled post standard installation
Previously, RHEL users configured Licensing, System (Subscription manager), and User Settings prior to
login screens. Starting with RHEL 9, the initial setup screens have been disabled by default to improve user experience. If you must run the initial setup for user creation or license display, install the following packages based on the requirements.
To install initial setup packages:
# yum install initial-setup initial-setup-gui
To enable initial setup while next reboot of the system.
# systemctl enable initial-setup
- Reboot the system to view initial setup.
For kickstart installations, add
initial-setup-gui to the packages section and enable the
firstboot --enable %packages @^graphical-server-environment initial-setup-gui %end
The rhsm command for machine provisioning via Kickstart installations for satellite is now available
rhsm command replaces the
%post scripts for machine provisioning on RHEL 9. The
rhsm command helps with all provisioning tasks such as registering the system, attaching RHEL subscriptions, and installing from a satellite instance. For more information, see the Registering and installing RHEL from Satellite using Kickstart section under the Performing an advanced RHEL installation guide.
Merged system purpose commands under the
subscription-manager syspurpose command
Previously, there were two different commands to set system purpose attributes;
subscriptions-manager. To unify all the system purpose attributes under one module, all the ‘addons’, ’role’, ’service-level’, and ‘usage’ commands from subscription-manager have been moved to the new submodule,
subscription-manager commands outside the new submodule are deprecated. The separate package (
python3-syspurpose) that provides the
syspurpose command line tool has been removed in RHEL 9.
This update provides a consistent way to view, set, and update all system purpose attributes using a single command of subscription-manager. This command replaces all the existing system purpose commands with their equivalent versions available as a new subcommand. For example,
subscription-manager role --set SystemRole becomes
subscription-manager syspurpose role --set SystemRole and so on.
For complete information about the new commands, options, and other attributes, see the
SYSPURPOSE OPTIONS section in the
subscription-manager man page.
New kickstart command -
timesource kickstart command is optional and it helps to set NTP, NTS servers, and NTP pools that provide time data. It also helps to control enabling or disabling the NTP services on the system. The
--ntpservers option from the timezone command has been deprecated and has been replaced with this new command.
Support for Anaconda boot arguments without inst. prefix is no longer available
Anaconda boot arguments without the
inst. prefix have been deprecated since RHEL 7. Support for these boot arguments has been removed in RHEL 9. To continue using these options, use the
For example, to force the installation program to run in the
text mode instead of the
graphical mode, use the following option:
Deprecated Kickstart commands and options
The following Kickstart commands and options have been deprecated on RHEL9.
timezone --ntpservers- use the
pwpolicy- use the Anaconda configuration files instead
Where only specific options are listed, the base command and its other options are still available and not deprecated. Using the deprecated commands in Kickstart files prints a warning in the logs. You can turn the deprecated command warnings into errors with the
inst.ksstrict boot option.
Removed Kickstart commands and options
The following Kickstart commands and options have been removed on RHEL 9. Using them in Kickstart files will cause an error.
install- use the subcommands or methods directly as commands
Where only specific options and values are listed, the base command and its other options are still available and not removed.
Removed Boot Options
The following boot options have been removed from Red Hat Enterprise Linux.
zram.serviceis not supported on RHEL 9. See zram-generator for more information.
The single language mode is not supported on RHEL 9.
The log level is always set to debug.
5.2. Image creation
Image Builder now supports multiversion image creation
As of Red Hat Enterprise Linux 9.0 Beta, Image Builder supports creating images of multiple RHEL major and minor releases, such as RHEL 8.3, 8.4, and 8.5.
Image Builder now supports file system configuration
As of Red Hat Enterprise Linux 9.0 Beta, Image Builder provide support for users to specify a custom filesystem configuration in blueprints to create images with a specific disk layout, instead of using the default layout configuration.
Image builder can create bootable ISO Installer images
You can use Image Builder to create bootable ISO Installer images. These images consist of a tarball that contains a root file system which you can use to install directly to a bare metal server.