Commands to live-upgrade CentOS Streams 8 -> 9

centos8-9.sh

#
yum upgrade
reboot
dnf install epel-release
dnf install rpmconf
dnf install yum-utils
rpmconf -a  # answer "n" to both things
package-cleanup --leaves
package-cleanup --orphans
dnf install https://mirror.stream.centos.org/9-stream/BaseOS/x86_64/os/Packages/centos-stream-release-9.0-12.el9.noarch.rpm https://mirror.stream.centos.org/9-stream/BaseOS/x86_64/os/Packages/centos-stream-repos-9.0-12.el9.noarch.rpm https://mirror.stream.centos.org/9-stream/BaseOS/x86_64/os/Packages/centos-gpg-keys-9.0-12.el9.noarch.rpm
curl -O https://dl.fedoraproject.org/pub/epel/epel-release-latest-9.noarch.rpm
curl -O https://dl.fedoraproject.org/pub/epel/epel-next-release-latest-9.noarch.rpm
rpm -Uvh *.rpm
yum update
dnf clean all
rpm -e `rpm -q kernel`
dnf -y --releasever=9 --allowerasing --setopt=deltarpm=false distro-sync
dnf clean all
reboot
rm -f /var/lib/rpm/__db*
rpm --rebuilddb
dnf -y groupupdate "Core" "Minimal Install"