Upgrade from RHEL 7 to RHEL 8 Using Leapp Utility
This guide is all about taking you through the step by step process of performing in-place upgrade from RHEL 7 to RHEL 8 using the Leapp utility.
RHEL7 maintenance support phase will come to an end in June 2024 hence the need to upgrade to the next available major release – RHEL 8.
Check the current RHEL version using the following command:
# cat /etc/os-release NAME="Red Hat Enterprise Linux Server" VERSION="7.9 (Maipo)" ID="rhel" ID_LIKE="fedora" VARIANT="Server" ...
Ensure you have a valid RHEL subscription. You can register and subscribe through subscription manager:
subscription-manager register --username xxxx --password xxxxx
Enable repos
Ensure that you have enabled the required repositories required for the upgrade. We need the Base repository(rhel-7-server-rpms) and the Extras repository(rhel-7-server-extras-rpms) where leapp and its dependencies are derived from.
subscription-manager repos --enable rhel-7-server-rpms --enable rhel-7-server-extras-rpms
Expected output:
Repository 'rhel-7-server-rpms' is enabled for this system. Repository 'rhel-7-server-extras-rpms' is enabled for this system.
Verify the repos
We need to verify that all expected RHEL 7 repositories are enabled in the server that we are upgrading through the command below:
subscription-manager repos --list-enabled | grep "^Repo ID"
Expected Output:
Repo ID: rhel-7-server-extras-rpms Repo ID: rhel-7-server-rpm
Update All Packages
Ensure that all packages have been updated to the latest version on your RHEL 7 instance. You can use yum utility to do it.
yum update -y
Reboot
Reboot the RHEL 7 instance to ensure that you’re running the latest kernel.
reboot
Install leapp
Use yum to install the Leapp utility.
yum install leapp -y
Expected Output:
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager rhel-7-server-extras-rpms | 3.4 kB 00:00:00 rhel-7-server-rpms | 3.5 kB 00:00:00 ... Installed: leapp.noarch 0:0.15.1-1.el7_9 ... python2-dnf.noarch 0:4.0.9.2-2.el7_9 python2-hawkey.x86_64 0:0.22.5-2.el7_9 python2-leapp.noarch 0:0.15.1-1.el7_9 Complete!
Note:
Leapp data files are now a part of the leapp-repository package. Therefore, you no longer need to manually download these files.
Optionally, the leap files can be downloaded from here. You need login credentilas to be able to download as only Subscribers can view this attachment.
Leapp Pre-upgrade
We use leapp preupgrade command to assess the upgradability of the system. The Leapp utility collects data about the system and generates a pre-upgrade report. This report provides a summary of potential problems and suggests recommended solutions to these problems.
leapp preupgrade --target 8.10
Analyze the report at the end. It’s key that you review the pre-upgrade report in the generated /var/log/leapp/leapp-report.txt and manually resolve reported inhibitors using the command-line interface(CLI). As an alternative, you can answer the true or false question by running the following command:
leapp answer --section <question_section>.<field_name>=<answer>
Fix Inhibitor Examples
leapp answer --section remove_pam_pkcs11_module_check.confirm=True; leapp answer --section authselect_check.confirm=True; rmmod pata_acpi floppy;
Inhibitors prevent you from upgrading until you have resolved them. The report contains the following risk factor levels:
High  : Very likely to result in a deteriorated system state.
Medium: Can impact both the system and applications.Low  : Should not impact the system but can have an impact on applications.Info  : Informational with no expected impact to the system or applications.
==> Processing phase Reports
====> * verify_check_results
Check all dialogs and notify that user needs to make some choices.
====> * verify_check_results
Check all generated results messages and notify user about them.
============================================================
UPGRADE INHIBITED
============================================================
Upgrade has been inhibited due to the following problems:
1. Inhibitor: Multiple devel kernels installed
2. Inhibitor: Missing required answers in the answer file
3. Inhibitor: Missing required answers in the answer file
Consult the pre-upgrade report for details and possible remediation.
============================================================
UPGRADE INHIBITED
============================================================
Debug output written to /var/log/leapp/leapp-preupgrade.log
============================================================
REPORT
============================================================
A report has been generated at /var/log/leapp/leapp-report.json
A report has been generated at /var/log/leapp/leapp-report.txt
============================================================
END OF REPORT
============================================================
Answerfile has been generated at /var/log/leapp/answerfile
Review the Inhibitors and High’s from the report – /var/log/leapp/leapp-report.txt
# cat /var/log/leapp/leapp-report.txt Risk Factor: high (inhibitor) Title: Multiple devel kernels installed Summary: DNF cannot produce a valid upgrade transaction when multiple kernel-devel packages are installed. Remediation: [hint] Remove all but one kernel-devel packages before running Leapp again. [command] yum -y remove kernel-devel-3.10.0-1160.99.1.el7 Key: 8ceea81afbbb1a329b7d82ca7212b21509e5b256 ---------------------------------------- Risk Factor: high (inhibitor) Title: Missing required answers in the answer file Summary: One or more sections in answerfile are missing user choices: remove_pam_pkcs11_module_check.confirm For more information consult https://leapp.readthedocs.io/en/latest/dialogs.html Remediation: [hint] Please register user choices with leapp answer cli command or by manually editing the answerfile. [command] leapp answer --section remove_pam_pkcs11_module_check.confirm=True Key: d35f6c6b1b1fa6924ef442e3670d90fa92f0d54b ---------------------------------------- Risk Factor: high (inhibitor) Title: Missing required answers in the answer file Summary: One or more sections in answerfile are missing user choices: authselect_check.confirm For more information consult https://leapp.readthedocs.io/en/latest/dialogs.html Remediation: [hint] Please register user choices with leapp answer cli command or by manually editing the answerfile. [command] leapp answer --section authselect_check.confirm=True Key: 68c3ee4354bd3c4e56697a9c34a9be5ce450ecf8 ---------------------------------------- .....
Fix Leapp Pre-upgrade Inhibitors
Remove kernel-devel packages
As recommended by the Leapp report, we need to remove all kernel-devel packages before running leapp preupgrade again.
yum -y remove kernel-devel-3.10.0-1160.*
Remove kernel modules/drivers that have been removed in RHEL 8
Inhibitor: Detected loaded kernel drivers (pata_acpi & floppy) which have been removed in RHEL 8.
Solution: rmmod pata_acpi – Support for this device driver has been removed in RHEL 8.
rmmod pata_acpi floppy
Fix PAM Modules
Inhibitor:Â Missing required answers in the answer file.
Solution:Â Execute the command given under command section, in my case:
leapp answer --section remove_pam_pkcs11_module_check.confirm=True leapp answer --section authselect_check.confirm=True
After fixing the inhibitors, run the leapp preupgrade command again and validate that you get a clean report before doing the actual leapp upgrade as shown below:
Transaction Summary
=============================================================================================================================================================
Install 523 Packages
Upgrade 1283 Packages
Remove 243 Packages
Downgrade 21 Packages
Total size: 1.7 G
Total download size: 1.6 G
Downloading Packages:
Check completed.
====> * check_systemd_services_tasks
Inhibit the upgrade if SystemdServicesTasks tasks are in conflict
...
Debug output written to /var/log/leapp/leapp-preupgrade.log
============================================================
REPORT
============================================================
A report has been generated at /var/log/leapp/leapp-report.json
A report has been generated at /var/log/leapp/leapp-report.txt
============================================================
END OF REPORT
============================================================
Answerfile has been generated at /var/log/leapp/answerfile
Performing the upgrade from RHEL 7 to RHEL 8
In case you get this error(XFS ftype=0) during leapp upgrade , try the solution below and try leapp upgrade again from the same terminal.
2023-09-06 12:29:24.164 ERROR PID: 30154 leapp.workflow.Download.dnf_package_download: DNF execution failed:
============================================================
ERRORS
============================================================
2023-09-06 12:29:25.674732 [ERROR] Actor: dnf_package_download
Message: There is not enough space on the file system hosting /var/lib/leapp directory to extract the packages.
Summary:
Hint: Please follow the instructions in the 'XFS ftype=0 case' section of the article at: link: https://access.redhat.com/solutions/5057391
============================================================
END OF ERRORS
============================================================
Debug output written to /var/log/leapp/leapp-upgrade.log
============================================================
REPORT
============================================================
A report has been generated at /var/log/leapp/leapp-report.json
A report has been generated at /var/log/leapp/leapp-report.txt
============================================================
END OF REPORT
============================================================
Create a python file – evaluate-ovl-size.py in /tmp and paste this code below:
#!/usr/libexec/platform-python
#
# DISCLAIMER: this script is not supported by Red Hat.
# Usage: ./eval-ovl-size.py
# Give a rough estimate of the required available space to in-place upgrade.
MIN_SIZE = 1024 # MB
EXTRA_MARGIN = 15 # %
import os, os.path, subprocess
def _shell(command):
# works with python2.7 (el7) as well as python3 (el8)
p = subprocess.Popen(command,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
close_fds=True,
shell=True,
universal_newlines=True)
output = []
while True:
line = p.stdout.readline().rstrip('\n')
if line:
output.append(line)
else:
break
return output
{{ More Code }}
Make the script executable and then run it:
chmod +x evaluate-ovl-size.py ./evaluate-ovl-size.py
Expected output:
[root@host01 tmp]# ./evaluate-ovl-size.py == Summary ==/var/lib/leappresides on the/varpartition Current available space in/var: 48529 MB Installed size for all RPMs: 3127 MB == XFS ftype=0 case == -> Adjust $LEAPP_OVL_SIZE before running Leapp: # export LEAPP_OVL_SIZE=3596 -> Required space in the/varpartition is: NumberOfXfsMountedPartitions * LEAPP_OVL_SIZE = 22600 MB -> If Leapp/DNF requires again more space: - adjust $LEAPP_OVL_SIZE with a bigger size - AND extend the/varpartition accordingly. For more information, please read https://access.redhat.com/solutions/5057391
Run the below command as suggested by the ouput above and try leapp upgrade again. This will consume more space than normal in /var. Please ensure that /var has enough space.
export LEAPP_OVL_SIZE=3596
Leapp Upgrade
Before the actual upgrade happens, Leapp performs the leapp preupgrade phase to ascertain that the system is upgradable. If the system is upgradable, Leapp downloads necessary data and prepares an RPM transaction for the upgrade process.
# leapp upgrade --target 8.10 ==> Processing phaseconfiguration_phase====> * ipu_workflow_config IPU workflow config actor ==> Processing phaseFactsCollection====> * scanzfcp In case of s390x architecture, check whether ZFCP is used. ====> * tcp_wrappers_config_read Parse tcp_wrappers configuration files /etc/hosts.{allow,deny}. ====> * scan_pkg_manager Provides data about package manager (yum/dnf) ====> * scan_grub_device_name Find the name of the block device where GRUB is located ====> * source_boot_loader_scanner Scans the boot loader configuration on the source system. ====> * scan_subscription_manager_info Scans the current system for subscription manager information ... ... Transaction Summary ================================================================================ Install 200 Packages Total download size: 111 M Installed size: 707 M Downloading Packages: (1/200): pinentry-1.1.0-2.el8.x86_64.rpm 84 kB/s | 100 kB 00:01 (2/200): libxkbcommon-0.9.1-1.el8.x86_64.rpm 88 kB/s | 116 kB 00:01 ... Transaction Summary ============================================================================================================================================================= Install 523 Packages Upgrade 1283 Packages Remove 243 Packages Downgrade 21 Packages Total size: 1.7 G Total download size: 1.6 G DNF will only download packages, install gpg keys, and check the transaction. Downloading Packages: [SKIPPED] grub2-tools-minimal-2.02-148.el8_8.1.x86_64.rpm: Already downloaded (201/1824): perl-Compress-Raw-Zlib-2.081-1.el8. 72 kB/s | 68 kB 00:00 (202/1824): adwaita-gtk2-theme-3.22.3-4.el8.x86 125 kB/s | 132 kB 00:01 (203/1824): libcacard-2.7.0-2.el8_1.x86_64.rpm 174 kB/s | 52 kB 00:00 (204/1824): atk-2.28.1-1.el8.x86_64.rpm 446 kB/s | 272 kB 00:00 (205/1824): glusterfs-cli-6.0-56.4.el8.x86_64.r 463 kB/s | 194 kB 00:00 (206/1824): glusterfs-api-6.0-56.4.el8.x86_64.r 329 kB/s | 99 kB 00:00 .... (1824/1824): linux-firmware-20230404-114.git2e9 1.5 MB/s | 264 MB 02:50 -------------------------------------------------------------------------------- Total 2.7 MB/s | 1.6 GB 09:42 Running transaction check Transaction check succeeded. Running transaction test Transaction test succeeded. Complete! The downloaded packages were saved in cache until the next successful transaction. You can remove cached packages by executing 'dnf clean packages'. ==> Processing phaseInterimPreparation====> * remove_upgrade_artifacts Removes artifacts left over by previous leapp runs ====> * efi_interim_fix Adjust EFI boot entry for first reboot ====> * upgrade_initramfs_generator Creates the upgrade initramfs ====> * dnf_dry_run Actor that invokes DNF to download the RPMs required for the upgrade transaction. Applying transaction workaround - remove obsolete RPM GPG keys from RPM DB Applying transaction workaround - yum config fix Applying transaction workaround - import trusted gpg keys to RPM DB Last metadata expiration check: 0:18:31 ago on Sun Sep 3 22:15:16 2023. Dependencies resolved. ============================================================================================================================================================= .... Total size: 1.7 G DNF will only download packages, install gpg keys, and check the transaction. Downloading Packages: Running transaction check Transaction check succeeded. Running transaction test Transaction test succeeded. Complete! ====> * add_upgrade_boot_entry Add new boot entry for Leapp provided initramfs. A reboot is required to continue. Please reboot your system. Debug output written to /var/log/leapp/leapp-upgrade.log ============================================================ REPORT ============================================================ A report has been generated at /var/log/leapp/leapp-report.json A report has been generated at /var/log/leapp/leapp-report.txt ============================================================ END OF REPORT ============================================================ Answerfile has been generated at /var/log/leapp/answerfile
Reboot the system
Once all the steps executed successfully, reboot the system. The system boots into a RHEL 8-based initial RAM disk image, initramfs. Leapp upgrades all packages and automatically reboots to the RHEL 8 system.
Once the system boots up, connect through ssh and verify the RHEL version:
ssh [email protected] ***********WARNING*****************WARNING*****************WARNING************* *This system is for the use of authorized users only. Any or all uses of this * *system and all files on this system may be intercepted, monitored, recorded, * *copied, audited,inspected, and disclosed to authorized organizational and law* *enforcement personnel. Your access is strictly limited to applicable services* *of the system for which you have obtained written authorization, and will be * *governed by the organizations Security Policy & Acceptable Usage Standard. * * * * Unauthorized or improper use of this system is strictly prohibited and may * *result in administrative disciplinary action and/or civil charges/criminal * *penalties. By continuing to use this system you indicate your awareness of * *and consent to these terms and conditions of use. LOG OFF IMMEDIATELY (Press * *CTRL-D) if you do not agree to the conditions stated in this warning. * ************WARNING*****************WARNING*****************WARNING************ [email protected]'s password: We trust you have received the usual lecture from the local System Administrator. It usually boils down to these three things: #1) Respect the privacy of others. #2) Think before you type. #3) With great power comes great responsibility. [technnix@node01 ~]$ sudo -i [root@node01 ~]# cat /etc/os-release NAME="Red Hat Enterprise Linux" VERSION="8.10 (Ootpa)" ID="rhel" ID_LIKE="fedora" VERSION_ID="8.10" PLATFORM_ID="platform:el8" PRETTY_NAME="Red Hat Enterprise Linux 8.10 (Ootpa)" ANSI_COLOR="0;31" CPE_NAME="cpe:/o:redhat:enterprise_linux:8::baseos" HOME_URL="https://www.redhat.com/" DOCUMENTATION_URL="https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8" BUG_REPORT_URL="https://bugzilla.redhat.com/" REDHAT_BUGZILLA_PRODUCT="Red Hat Enterprise Linux 8" REDHAT_BUGZILLA_PRODUCT_VERSION=8.10 REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux" REDHAT_SUPPORT_PRODUCT_VERSION="8.10"
Post Upgrade Tasks
- Remove all packages from the
excludelist:
# yum config-manager --save --setopt exclude=''
2. List and Remove old kernels for RHEL 7
# yum list kernel Updating Subscription Management repositories. This system is registered with an entitlement server, but is not receiving updates. You can use subscription-manager to assign subscriptions. Red Hat Enterprise Linux 8 for x86_64 - AppStream (RPMs) 1.6 MB/s | 59 MB 00:36 Red Hat Enterprise Linux 8 for x86_64 - BaseOS (RPMs) 3.0 MB/s | 63 MB 00:21 Last metadata expiration check: 0:00:01 ago on Sun 03 Sep 2023 11:10:56 PM EAT. Installed Packages kernel.x86_64 3.10.0-1160.88.1.el7 @System kernel.x86_64 3.10.0-1160.99.1.el7 @System kernel.x86_64 4.18.0-477.21.1.el8_8 @System
Uninstall 3.10.x kernels from the system for RHEL 7.
# yum -y remove kernel-3.10.0-* Updating Subscription Management repositories. This system is registered with an entitlement server, but is not receiving updates. You can use subscription-manager to assign subscriptions. Dependencies resolved. ====================================================================================================================================================================================================================== Package Architecture Version Repository Size ====================================================================================================================================================================================================================== Removing: kernel x86_64 3.10.0-1160.88.1.el7 @System 66 M kernel x86_64 3.10.0-1160.99.1.el7 @System 66 M Transaction Summary ====================================================================================================================================================================================================================== Remove 2 Packages ... Removed: kernel-3.10.0-1160.88.1.el7.x86_64 kernel-3.10.0-1160.99.1.el7.x86_64 Complete!
3. Remove remaining RHEL 7 packages, including the remaining Leapp packages.
Determine old kernel versions:
# cd /lib/modules && ls -ld *.el7* drwxr-xr-x. 3 root root 19 Jun 10 12:16 3.10.0-1160.59.1.el7.x86_64 drwxr-xr-x 3 root root 19 Sep 3 20:49 3.10.0-1160.81.1.el7.x86_64 drwxr-xr-x 7 root root 4096 Sep 3 22:54 3.10.0-1160.88.1.el7.x86_64 drwxr-xr-x 7 root root 4096 Sep 3 22:54 3.10.0-1160.99.1.el7.x86_64 drwxr-xr-x. 3 root root 19 Jan 27 2023 3.10.0-862.9.1.el7.x86_64
Remove the modules and directories
# rm -rf /lib/modules/*el7*
5. Reboot the system
# reboot
Conclusion
We have come to the end of this guide. I hope you managed to upgrade your system from RHEL 7 to RHEL 8. Keep it here for more similar articles.
