How to upgrade from RHEL 8 to RHEL 9

Red Hat On 2022 year 5 month 17 Announced full launch RHEL 9. This is a RHEL（Red Hat Enterprise Linux） Latest version , It has many features and enhancements .

Notable highlights include ：

• The new software version includes PHP 8.0、Ruby 3.0、Perl 5.32、Node.JS 16 wait .

• SELinux and OpenSSH Security enhancements in services .

• Use Web Console enhanced performance monitoring .

• from Web Console for real-time kernel patching .

• Introduce custom... For creating multiple formats RHEL Image generator tools for system images .

A complete list of all the interesting new features and enhancements , Please visit RHEL 9 Release notes ： https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html-single/9.0_release_notes/index

In this guide , We'll show you step-by-step how to start from RHEL 8 Upgrade to RHEL 9.

precondition

Before we start , This is what you need .

• RHEL 8.6 An example of

• Fast and stable Internet connection for performing upgrades

• Minimum boot partition 100 MB

After meeting the minimum requirements , Let's get started .

1. Delete 'tmp_leapp_py3' Catalog

If you have ever been from RHEL 7 Migrate to RHEL 8, Then you need to delete /root/tmp_leapp_py3 Catalog . Use the following rm command

$ sudo rm -Rf /root/tmp_leapp_py3

however , If you installed it completely new RHEL 8 Start , Please skip this step and continue .

2. Make sure your system has an effective Red Hat subscribe

Upgrade as planned , Please make sure you have a valid Red Hat subscribe . To verify that you have an active subscription , Please run the following command ：

$ sudo subscription-manager list --installed

If your system has a subscription , You get the following output .

If your system is not registered to Red Hat Subscription management , Please register it on the command line , As shown in the figure .

The username and password credentials are for you Red Hat Login details of the account .

3. Ensure that the appropriate warehouse is enabled

Next , You need to make sure that the required repository is enabled . This command enables 64 position Intel Architecturally Base and App Stream warehouse .

$ sudo subscription-manager repos --enable rhel-8-for-x86_64-baseos-rpms --enable rhel-8-for-x86_64-appstream-rpms

4. Lock the system to RHEL 8.6

Next , Put your RHEL The system is locked to RHEL 8.6. This marks the beginning of the upgrade RHEL edition .

$ sudo subscription-manager release --set 8.6

5. Enable RHUI Warehouse （ Only applicable to AWS example ）

If you are running hosted on AWS Upper RHEL 8 example , You need to enable and install the required Red Hat Update Infrastructure Warehouse , In order to prepare the system for the upgrade .

$ sudo dnf config-manager –set-enabled rhui-client-config-server-8
$ sudo dnf -y install rh-amazon-rhui-client-ha leapp-rhui-aws

6. Update the software package to the latest version

Next , Be sure to upgrade all software packages to the latest version .

$ sudo dnf update

After completion , Restart the system .

$ sudo reboot

7. install leapp-upgrade software package

Next , install leapp-upgrade Tools , The tool will automatically start from RHEL 8 Upgrade to RHEL 9

$ sudo dnf install leapp-upgrade

8. remove Versionlock plug-in unit

Versionlock Is a plug-in , It can protect the package from being upgraded to a new version . If you have set this , You need to clear the following .

$ sudo dnf versionlock clear

9. modify Firewalld To configure

In order to upgrade smoothly , You need to Firewalld Disabled in configuration AllowZoneDrifting value . therefore , visit firewalld The configuration file .

$ sudo vi /etc/firewalld/firewalld.conf

Scroll down and comment AllowZoneDrifting attribute .

Save your changes and exit the configuration file .

10. Perform pre upgrade

Before performing the actual upgrade , It is recommended to perform a pre upgrade check first . This simulates the actual upgrade , And report any errors that prevent the upgrade .

therefore , Run the following command to run the pre upgrade check .

$ sudo leapp preupgrade --target 9.0

This command checks all system configurations , Include kernel 、 The driver , And provide to be installed 、 Summary of the total number of packages upgraded and deleted . It also provides the number of packages to be downgraded and the total download size of new packages .

The pre upgrade check report is generated and saved in /var/log/leapp/leapp-report.json and /var/log/leapp/leapp-report.txt In the text file .

11. from RHEL 8 Upgrade to RHEL 9

here , We are ready to proceed from RHEL 8 To RHEL 9 In place upgrades of . So , Please run the following command

$ sudo leapp upgrade --target 9.0

Upgrade will download the new software package and upgrade the existing software package to the new version . Some outdated packages have also been removed , Some were downgraded . Under the fast and stable network connection , It takes about 20 minute .

Last , You will need to restart the system . Details about the upgrade are recorded or saved in /var/log/leapp/leapp-report.json and /var/log/leapp/leapp-report.txt In the text file .

12. choice RHEL-Upgrade-Initramfs GRUB entry

After reboot , from GRUB From the menu RHEL-Upgrade-Initramfs entry .

Next , Press CTRL + D Keep upgrading .

It takes quite a long time , So please wait patiently for the upgrade . After completion , The system will restart . This time, , You will see RHEL 9.0 Menu options for . Press “ ENTER ” Select this option

13. Log in to RHEL 9 System

On the login screen , Provide your login password and click “ ENTER ”

After logging in ,RHEL 9 The desktop will display the new look GNOME 42.

Besides , You can verify that the upgrade was successful by running the following command ：

$ cat /etc/redhat-release

Besides , Please confirm that it is RHEL Part of the subscription .

$ sudo subscription-manager list --installed

That's right , We have successfully completed from RHEL 8 To RHEL 9 In place upgrades of . When you start using RHEL 9 The system is running smoothly , Go and try the upgrade ！