RHEL 7.7 to CentOS 7.7

migration

URLBASE=http://vault.centos.org/7.7.1908/os/x86_64/Packages/
cd /tmp
mkdir TMP
cd TMP
wget $URLBASE/centos-indexhtml-7-9.el7.centos.noarch.rpm \
    $URLBASE/centos-release-7-7.1908.0.el7.centos.x86_64.rpm \
    $URLBASE/yum-3.4.3-163.el7.centos.noarch.rpm \
    $URLBASE/yum-plugin-fastestmirror-1.1.31-52.el7.noarch.rpm
subscription-manager remove --all
yum remove rhnlib abrt-plugin-bugzilla redhat-release-notes\* subscription-manager\*
rpm -e --nodeps redhat-release redhat-release-server redhat-indexhtml
rm -rf /usr/share/redhat-release*
rm -rf /usr/share/doc/redhat-release*
rpm -Uvh --replacefiles *.rpm 
yum clean all && rm -rf /var/cache/yum
yum makecache fast
yum upgrade
yum distro-sync
package-cleanup --orphans
cd .. && rm -rf TMP