AlmaLinux Wiki
# last updated: 2024-11-14

# ELevating CentOS 7 to AlmaLinux 9

This guide contains steps on how to upgrade your CentOS 7 machine to AlmaLinux OS 9. As the Leapp tool is designed to perform one-step upgrades, you need to split the upgrade process:

  • CentOS 7 to AlmaLinux 8
  • AlmaLinux 8 to AlmaLinux 9

The ELevate project supports a number of 3rd party repositories:

  • EPEL support is currently available for upgrades to AlmaLinux OS only.
  • Docker CE - for all supported operating systems.
  • MariaDB - for all supported operating systems.
  • Microsoft Linux Package Repositories - for all supported operating systems.
  • nginx - for all supported operating systems.
  • PostgreSQL - for all supported operating systems.
  • Imunify - for upgrades to EL 8.
  • KernelCare - for all supported operating systems.

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You can contribute to the project and add more 3rd party repositories support. See more on the Contribute page.

# Upgrade CentOS 7 to AlmaLinux 8

  • Update the system to get the latest updates and reboot your machine. NOTE: Since the CentOS 7 repositories are now offline you will need to swap to the CentOS vault, or you can use our CentOS 7 mirror that we've setup for use with ELevate:

    sudo curl -o /etc/yum.repos.d/CentOS-Base.repo https://el7.repo.almalinux.org/centos/CentOS-Base.repo
sudo yum upgrade -y
sudo reboot

  • Install elevate-release package with the project repo and GPG key.

    sudo yum install -y http://repo.almalinux.org/elevate/elevate-release-latest-el$(rpm --eval %rhel).noarch.rpm

  • Install leapp packages and upgrade data for AlmaLinux which is target OS:

    sudo yum install -y leapp-upgrade leapp-data-almalinux

  • Start a preupgrade check. In the meanwhile, the Leapp utility creates a special /var/log/leapp/leapp-report.txt file that contains possible problems and recommended solutions. No rpm packages will be installed at this phase.

    WARNING

    Preupgrade check will fail as the default install doesn't meet all requirements for upgrade.

    sudo leapp preupgrade

    This summary report will help you get a picture of whether it is possible to continue the upgrade.

    TIP

    In certain configurations, Leapp generates /var/log/leapp/answerfile with true/false questions. Leapp utility requires answers to all these questions in order to proceed with the upgrade.

  • The following fixes from the /var/log/leapp/leapp-report.txt file are the most popular for CentOS 7, but it's recommended to review the whole file.

    sudo rmmod pata_acpi
echo PermitRootLogin yes | sudo tee -a /etc/ssh/sshd_config
sudo leapp answer --section remove_pam_pkcs11_module_check.confirm=True

    Check the ELevate Frequent Issues page for known and frequent issues and guidance steps to solve them.

  • Start an upgrade. You'll be offered to reboot the system after this process is completed.

    sudo leapp upgrade
sudo reboot

  • A new entry in GRUB called ELevate-Upgrade-Initramfs will appear. The system will be automatically booted into it. See how the update process goes in the console.

  • After reboot, login to the system and check how the upgrade went. Verify that the current OS is the one you need. Check logs and packages left from the previous OS version, consider removing or updating them manually.

    cat /etc/redhat-release
cat /etc/os-release
rpm -qa | grep el7 
cat /var/log/leapp/leapp-report.txt
cat /var/log/leapp/leapp-upgrade.log

# Prepare the system for upgrade to AlmaLinux 9

When successfully upgraded to AlmaLinux 8 OS, consider performing these steps to prepare your system for upgrade to AlmaLinux 9:

  • Navigate to the /etc/ directory and use an editor of your choice to edit the yum.conf file. You need to remove everything from the exclude line especially that refers to elevate or leapp.

    # An example of yum.conf file:
    [main]
gpgcheck=1
installonly_limit=3
clean_requirements_on_remove=True
best=True
skip_if_unavailable=False
exclude=python2-leapp,snactor,leapp-upgrade-el7toel8,leapp

  • Then navigate to the /etc/dnf/ directory and use an editor of your choice to do the same in the dnf.conf file.

  • Now you can remove/manually upgrade packages left from CentOS 7 without any conflicts.

  • Check packages left from CentOS 7:

    rpm -qa | grep el7
    # An example output with a list of packages:
    leapp-upgrade-el7toel8-0.16.0-6.el7.elevate.17.noarch
yum-plugin-fastestmirror-1.1.31-54.el7_8.noarch
python2-leapp-0.14.0-1.el7.noarch
leapp-data-almalinux-0.1-6.el7.noarch
kernel-3.10.0-1160.102.1.el7.x86_64
kernel-3.10.0-1160.el7.x86_64
java-1.7.0-openjdk-headless-1.7.0.261-2.6.22.2.el7_8.x86_64
btrfs-progs-4.9.1-1.el7.x86_64
elevate-release-1.0-2.el7.noarch
leapp-0.14.0-1.el7.noarch

    As mentioned above, consider removing these packages or upgrading them manually to proceed with the upgrade to AlmaLinux 9.

    TIP

    If you face difficulties while removing the packages, the following command might help you:

    rpm -e --nodeps <package_name>

  • You can also check for the packages left from the upgrade process and remove them:

    rpm -qa | grep elevate
rpm -qa | grep leapp

  • Check whether you have the /root/tmp_leapp_py3 directory created and if so delete it.

    sudo rm -fr /root/tmp_leapp_py3

  • Clean up your machine.

    sudo dnf clean all

  • You may also have to remove old RSA/SHA1 GPG keys. List the keys:

    rpm -q gpg-pubkey --qf '%{NAME}-%{VERSION}-%{RELEASE}\t%{SUMMARY}\n'

    To remove them, use use the rpm -e command:

    rpm -e [keyname]

After these preparations are completed, you can upgrade your AlmaLinux 8 machine to AlmaLinux 9.

# Upgrading AlmaLinux 8 to AlmaLinux 9

  • Install elevate-release package with the project repo and GPG key.

    sudo yum install -y http://repo.almalinux.org/elevate/elevate-release-latest-el$(rpm --eval %rhel).noarch.rpm

  • Install leapp packages and upgrade data for AlmaLinux:

    sudo yum install -y leapp-upgrade leapp-data-almalinux

  • Start a preupgrade check. In the meanwhile, the Leapp utility creates a special /var/log/leapp/leapp-report.txt file that contains possible problems and recommended solutions. No rpm packages will be installed at this phase.

    WARNING

    Preupgrade check will fail as the default install doesn't meet all requirements for upgrading.

    sudo leapp preupgrade

    This summary report will help you get a picture of whether it is possible to continue the upgrade.

    TIP

    In certain configurations, Leapp generates /var/log/leapp/answerfile with true/false questions. Leapp utility requires answers to all these questions in order to proceed with the upgrade.

  • The following fixes from the /var/log/leapp/leapp-report.txt file are the most popular fixes for RHEL8-based operating systems:

    sudo sed -i "s/^AllowZoneDrifting=.*/AllowZoneDrifting=no/" /etc/firewalld/firewalld.conf
sudo leapp answer --section check_vdo.confirm=True

    You might also find the following issue in the leapp-report file that can interfere with the upgrade. Consider removing the file:

     Network configuration for unsupported device types detected
 Summary: RHEL 9 does not support the legacy network-scripts package that was deprecated in RHEL 8 in favor of NetworkManager. Files for device types that are not supported by NetworkManager are present in the system. Files with the problematic configuration:
   - /etc/sysconfig/network-scripts/ifcfg-eth0

    Check the ELevate Frequent Issues page for known and frequent issues and guidance steps to solve them.

  • Start an upgrade. You'll be offered to reboot the system after this process is completed.

    sudo leapp upgrade
sudo reboot

    TIP

    You might want to remove the make-devel package as it conflicts when running leapp upgrade and thus this step fails.

  • A new entry in GRUB called ELevate-Upgrade-Initramfs will appear. The system will be automatically booted into it. See how the update process goes in the console.

  • After reboot, login to the system and check how the upgrade went. Verify that the current OS is the one you need. Check logs and packages left from the previous OS version, consider removing or updating them manually.

    cat /etc/redhat-release
cat /etc/os-release
rpm -qa | grep el8
cat /var/log/leapp/leapp-report.txt
cat /var/log/leapp/leapp-upgrade.log

  • There will be outstanding nss_db package which should be removed and the system should be updated:

    dnf update --allowerasing

# Important Notes about the Upgrade Process

  • During the upgrade, ELevate uses a multitude of repositories to migrate and upgrade the system. Among them is the usage of the CRB repository. Important to note, if the CRB repository was not enabled on your system prior to using ELevate, it will remain disabled after the upgrade. This can cause future system updates via dnf to fail as one or more packages/package dependencies may now depend on packages within the CRB repository. The errors can look something like this:

    Error: 
Problem: package nss_db-2.34-100.el9_4.2.x86_64 from @System requires glibc(x86-64) = 2.34-100.el9_4.2, but none of the providers can be installed

cannot install both glibc-2.34-100.el9_4.2.alma.2.x86_64 from baseos and glibc-2.34-100.el9_4.2.x86_64 from @System
cannot install both glibc-2.34-100.el9_4.2.x86_64 from baseos and glibc-2.34-100.el9_4.2.alma.2.x86_64 from baseos
cannot install the best update candidate for package glibc-2.34-100.el9_4.2.x86_64
problem with installed package nss_db-2.34-100.el9_4.2.x86_64

    This issue can be resolved by enabling the CRB repository.

    While this is one of the most commonly encountered post-ELevate dnf repository related issues, additional or alternative issues may arise from similarly absent dnf repositories that are responsible for dependency resolution.

    To enable CRB or any other AlmaLinux repository, please reference this article

# Get Help

For more help and assistance reach out to us in the ~migration channel on the AlmaLinux Community Chat (opens new window).

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