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
Allow root SSH login with password
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:
# dnf install initial-setup initial-setup-gui
To enable initial setup after the 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
rhsm command for machine provisioning through Kickstart 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 in the Performing an advanced RHEL installation guide.
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:
Removed Kickstart commands and options
The following Kickstart commands and options have been removed from RHEL 9. Using them in Kickstart files causes 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:
RHEL 9 does not support the
zramservice. See the
zram-generator(8)man page 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
As of Red Hat Enterprise Linux 9.0:
Image Builder supports customized file system partitions on LVM
With support for customized file system partitions on LVM, if you add any file system customization to your system, the file systems are converted to an LVM partition.
Image Builder now supports file system configuration
As of Red Hat Enterprise Linux 9.0, Image Builder provides 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 GUI and CLI 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.