Howto migrate centos7 to 8x

rhel alternatives or derivatives:

• rockylinux
• almalinux
• openeuler
• springdale

cloud images:

https://wiki.vidalinux.org/index.php/Linux_cloud_images

distributions to migrate supported:

• CentOS 7 to AlmaLinux 8
• CentOS 7 to Rocky Linux 8
• CentOS 7 to Oracle Linux 8
• CentOS 7 to CentOS Stream 8

upgrade current system to latest:

yum update -y

verify your current version:

cat /etc/centos-release

install elevate-release package:

yum install http://repo.almalinux.org/elevate/elevate-release-latest-el7.noarch.rpm -y

install leapp-upgrade and migration-data:

Possible options are:

• leapp-data-almalinux
• leapp-data-centos
• leapp-data-oraclelinux
• leapp-data-rocky

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

start a preupgrade check:

leapp preupgrade

normally the check will fail, it’s normal because we need to do some tweaks:

  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

then run check again:

leapp preupgrade

if everything runs well, upgrade the system:

leapp upgrade

once the migration is completed, you’ll be offered to reboot the system:

reboot

select the new entry in grub called ELevate-Upgrade-Initramfs, wait for the upgrade process to finish.

when system is migrated to el8 run the following command to remove any el7 rpm package:

rpm -qa|grep el7|xargs rpm -e

centos8 to almalinux8

fix mirrors:

sed -i -e "s|mirrorlist=|#mirrorlist=|g" /etc/yum.repos.d/CentOS-*
sed -i -e "s|#baseurl=http://mirror.centos.org%7Cbaseurl=http://vault.centos.org%7Cg" /etc/yum.repos.d/CentOS-*

update your system to latest:

yum update -y

download deploy script:

curl -O https://raw.githubusercontent.com/AlmaLinux/almalinux-deploy/master/almalinux-deploy.sh

fix script permissions:

chmod +x almalinux-deploy.sh

run the script:

bash almalinux-deploy.sh

references

• https://wiki.almalinux.org/elevate/ELevate-quickstart-guide.html