# last updated: 2024-09-20

# ELevate Offline Guide

This guide describes steps to be performed to migrate an air-gapped machine that has no connection to the Internet but has network access to a private mirror. The process involves at least two hosts:

  • One with Internet access to be able to create local AlmaLinux and ELevate mirrors
  • Another machine with access to these private mirrors that will be migrated.

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If there's neither access to a private mirror nor the Internet, you'll have to use a data storage device to get local AlmaLinux and ELevate mirrors.

# Requirements

To migrate an air-gapped machine, you have to create a local mirror to receive updates. For this purpose, the recommended storage space is at least 500GB per major version. As there are currently two supported major versions (8 and 9) the storage space should be 1TB.

# Prerequisites

Several steps must be accomplished before migrating the system.

# Create a local AlmaLinux mirror

These steps are to be performed on a host with Internet access.

The rsync tool can be used to create a local mirror.

  • Synchronize with the official AlmaLinux mirror via rsync:

    /usr/bin/rsync -avSH --exclude='.~tmp~' --delete-delay --delay-updates rsync://rsync.repo.almalinux.org/almalinux/ /example-almalinux-mirror/
    
  • If needed, create a cron task to sync your local mirror periodically (we recommend updating the mirror every 3 hours):

    0 */3 * * * sleep $(((RANDOM\%3500)+1)) && /usr/bin/flock -n /var/run/almalinux_rsync.lock -c "/usr/bin/rsync -avSH --exclude='.~tmp~' --delete-delay --delay-updates rsync://rsync.repo.almalinux.org/almalinux/ /example-almalinux-mirror/"
    

    WARNING

    Don't forget to replace /example-almalinux-mirror/ directory with the directory you need.

# Create a local ELevate mirror

These steps are to be performed on a host with Internet access.

  • Synchronize with the official AlmaLinux ELevate mirror via rsync:

    /usr/bin/rsync -avSH --exclude='.~tmp~' --delete-delay --delay-updates  rsync://rsync.repo.almalinux.org/almalinux-elevate/ /example-elevate-mirror/
    
  • If needed, create a cron task to sync your local mirror periodically (we recommend updating the mirror every 3 hours):

    0 */3 * * * sleep $(((RANDOM\%3500)+1)) && /usr/bin/flock -n /var/run/almalinux_rsync.lock -c "/usr/bin/rsync -avSH --exclude='.~tmp~' --delete-delay --delay-updates rsync://rsync.repo.almalinux.org/almalinux-elevate/ /example-elevate-mirror/"
    

    WARNING

    Don't forget to replace /example-elevate-mirror/ directory with the directory you need.

# Add access to the private ELevate mirror

These steps are to be performed on a host with access to a private ELevate mirror that will be migrated.

To be able to install ELevate packages you need to add the local ELevate mirror to your server.

  • Navigate to the /etc/yum.repos.d directory. Use an editor tool of choice, for example, vi or mcedit to create a repository elevate.repo file. It should contain data from your local ELevate repository. Enter the data to the file according to the example:
     [ELevate]
     name=ELevate for EL$releasever
     baseurl=http://mirror.example.com/elevate/el$releasever/$basearch/ 
     enabled=1
     gpgcheck=1
     gpgkey=http://mirror.example.com/elevate/RPM-GPG-KEY-ELevate
    

# Migrate CentOS 7 to AlmaLinux 8

These steps are to be performed on a host with access to private mirrors that will be migrated.

# Install ELevate packages

  • Install leapp packages and migration data for the target OS you want to upgrade to from the private mirror:

    sudo yum install -y leapp-upgrade leapp-data-almalinux
    
  • Navigate to the /etc/leapp/files/ directory to update the leapp configuration file.

  • Open the leapp_upgrade_repositories.repo file and use an editor tool of choice, for example vi or mcedit, to replace baseurl link for each repository with a local AlmaLinux mirror directory. Pay attention, that links should belong to a major version you want your system to migrate to.

    [almalinux8-baseos] 
    name=AlmaLinux 8 - BaseOS
    baseurl=http://mirror.example.com/almalinux/el$releasever/$basearch/ 
    enabled=1
    gpgcheck=1
    gpgkey=http://mirror.example.com/almalinux/RPM-GPG-KEY-AlmaLinux
    

# Perform the migration

Once you've edited the leapp_upgrade_repositories.repo file to match your local mirror, you can start the migration to AlmaLinux 8.

  • 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 migration.

    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 migration 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
    
  • If your next stage is to migrate to AlmaLinux 9 proceed with the next steps to prepare your system.

# Prepare the system for migration to AlmaLinux 9

When successfully migrated to AlmaLinux 8 OS, consider performing these steps to prepare your system for migration 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 migration 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 migration 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 migrate your AlmaLinux 8 machine to AlmaLinux 9.

# Migrate AlmaLinux 8 to AlmaLinux 9

These steps are to be performed on a host with access to private mirrors that will be migrated.

If you previously migrated your airgapped system to AlmaLinux 8, your local repositories of AlmaLinux and ELevate should still be present. If this migration is the first one, you have to create your local mirrors first to proceed with the migration.

# Install ELevate packages

  • Install leapp packages and migration data for the target OS you want to upgrade to from the private mirror:

    sudo yum install -y leapp-upgrade leapp-data-almalinux
    
  • Navigate to the /etc/leapp/files/ directory to update the leapp configuration file.

  • Open the leapp_upgrade_repositories.repo file and use an editor tool of choice, for example vi or mcedit, to replace baseurl link for each repository with a local AlmaLinux mirror directory. Pay attention, that links should belong to a major version you want your system to migrate to.

    [almalinux9-baseos] 
    name=AlmaLinux 9 - BaseOS
    baseurl=http://mirror.example.com/almalinux/el$releasever/$basearch/ 
    enabled=1
    gpgcheck=1
    gpgkey=http://mirror.example.com/almalinux/RPM-GPG-KEY-AlmaLinux
    

# Perform the migration

Once you've edited the leapp_upgrade_repositories.repo file to match your local mirror, you can start the migration to AlmaLinux 9.

  • 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 migration.

    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 migration. 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 migration 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
    

# Get Help

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