Upgrade to RHEL 10 from RHEL 9: A Comprehensive Step-by-Step Guide
Staying current with your operating system is critical for security, performance, and access to the latest features. For administrators running Red Hat Enterprise Linux (RHEL), the upgrade from version 9 to 10 marks a significant step forward. Fortunately, Red Hat provides a robust, supported framework for performing an in-place upgrade, minimizing downtime and simplifying the transition.
This guide will walk you through the entire process using the Leapp utility, the official tool for RHEL upgrades. By following these steps carefully, you can ensure a smooth and successful migration to RHEL 10.
Before You Begin: Essential Prerequisites
Preparation is the most important phase of any system upgrade. Rushing this stage can lead to data loss or extended downtime. Before initiating the upgrade process, ensure you have completed the following critical prerequisites.
- Create a Full System Backup: This is the most crucial step. Before making any changes, perform a complete and verified backup of your RHEL 9 system. Use your organization’s standard backup tools, whether it’s system snapshots, LVM snapshots, or a full file-level backup. A reliable backup is your only safety net if something goes wrong.
- Update Your RHEL 9 System: Ensure your current system is fully patched and up-to-date. This resolves potential conflicts and ensures you are starting from a stable, known state. Run the following command:
bash
sudo dnf update -y
After the update is complete, reboot the system to apply all changes, especially if a new kernel was installed.
bash
sudo reboot
- Verify Your RHEL Subscription: The upgrade process requires a valid Red Hat subscription to access the necessary repositories and packages. Confirm your subscription status with:
bash
sudo subscription-manager list --installed
- Check Disk Space: The upgrade process will download new packages and create temporary files. Ensure you have sufficient free space, particularly in the
/and/bootpartitions. A lack of space is a common cause of upgrade failure.
The In-Place Upgrade Process: Step-by-Step
With the prerequisites met, you can now begin the upgrade using the Leapp utility. This tool is designed to analyze the system, report potential issues, and then perform the upgrade.
Step 1: Install the Leapp Utility
First, you need to install the leapp package and its associated data files, which contain the necessary upgrade paths and rules.
sudo dnf install -y leapp-upgrade
Step 2: Run the Pre-Upgrade Analysis
This is arguably the most important operational step. The leapp preupgrade command simulates the upgrade process without making any changes to your system. It performs hundreds of checks to identify potential problems, such as unsupported software, deprecated configurations, or package conflicts that could block the upgrade.
sudo leapp preupgrade --target 10.0
Once the analysis is complete, Leapp will generate a detailed report. You must review this report carefully. It is located at /var/log/leapp/leapp-report.txt. The report will categorize issues as:
- Inhibitors: These are critical issues that will block the upgrade until they are resolved.
- High Risk: Serious issues that could cause system instability or application failure post-upgrade.
- Medium/Low Risk: Informational items or minor issues to be aware of.
Step 3: Remediate All Inhibitors
Do not proceed with the upgrade until you have addressed every issue flagged as an “Inhibitor” in the leapp-report.txt file. The report provides detailed explanations and often includes suggested solutions for each problem. Common inhibitors include the use of unsupported kernel modules, incompatible third-party repositories, or deprecated packages.
After resolving an issue, you can re-run the leapp preupgrade command to confirm it has been fixed. Repeat this process until the pre-upgrade check completes without any inhibitors.
Step 4: Perform the Upgrade
Once the pre-upgrade analysis is clean, you are ready to begin the actual upgrade. This command will download all the necessary RHEL 10 packages and prepare the system for the transition.
sudo leapp upgrade --target 10.0
This process can take a significant amount of time depending on your system’s hardware and internet connection speed. Do not interrupt this process.
Step 5: Reboot the System
After the leapp upgrade command completes successfully, it will prompt you to reboot the system. This final reboot is what actually performs the upgrade.
sudo reboot
During the reboot, the system will boot into a special upgrade-specific initial RAM disk environment. You will see the system applying the new RHEL 10 packages. The system will automatically reboot again once this phase is complete.
Post-Upgrade Verification and Cleanup
After the final reboot, your system should be running Red Hat Enterprise Linux 10. It is essential to verify that the upgrade was successful and that your services and applications are functioning correctly.
Confirm the OS Version: Log in and check the operating system version.
cat /etc/redhat-releaseThe output should show Red Hat Enterprise Linux release 10.0 or later.
Check the Kernel Version: Verify that the new RHEL 10 kernel is active.
uname -rVerify System Services: Check for any failed services that may not have started correctly after the upgrade.
systemctl list-units --type=service --state=failedInvestigate and resolve any failed services.
Test Critical Applications: This is a crucial final validation step. Thoroughly test all business-critical applications hosted on the server to ensure they are fully functional on RHEL 10.
By following this structured approach, you can confidently upgrade your systems from RHEL 9 to RHEL 10, leveraging the latest advancements in security, stability, and enterprise features that Red Hat provides.
Source: https://www.linuxtechi.com/upgrade-rhel-9-to-rhel-10-step-by-step-guide/
