只负责记录, 升级出了问题责任自负.

yum -y install epel-release yum-utils rpmconf  dnf
yum remove 

# 
# package-cleanup --leaves
# package-cleanup --orphans
#

dnf -y remove yum yum-metadata-parser libsysfs  
dnf upgrade -y
dnf upgrade -y http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/{centos-release-8.1-1.1911.0.8.el8.x86_64.rpm,centos-gpg-keys-8.1-1.1911.0.8.el8.noarch.rpm,centos-repos-8.1-1.1911.0.8.el8.x86_64.rpm}

dnf upgrade -y epel-release
dnf clean all
rpm -e `rpm -q kernel`
rpm -e --nodeps sysvinit-tools
dnf -y --releasever=8 --allowerasing --setopt=deltarpm=false distro-sync
dnf -y install kernel-core
dnf -y groupupdate Core "Minimal Install"
cat /etc/redhat-release

centos8的三个包centos-release centos-gpg-keys centos-repos版本会有变动, 操作的时候需要注意选择更新.

也可以不用http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/ ,选用centos vault的库.