sed -i 's|^#baseurl=http://mirror.centos.org/centos/\$releasever/os/\$basearch/|baseurl=http://vault.centos.org/7.9.2009/os/\$basearch/|g' /etc/yum.repos.d/CentOS-Base.repo sed -i 's|^#baseurl=http://mirror.centos.org/centos/\$releasever/updates/\$basearch/|baseurl=http://vault.centos.org/7.9.2009/os/\$basearch/|g' /etc/yum.repos.d/CentOS-Base.repo sed -i 's|^#baseurl=http://mirror.centos.org/centos/\$releasever/extras/\$basearch/|baseurl=http://vault.centos.org/7.9.2009/os/\$basearch/|g' /etc/yum.repos.d/CentOS-Base.repo sed -i 's|^#baseurl=http://mirror.centos.org/centos/\$releasever/centosplus/\$basearch/|baseurl=http://vault.centos.org/7.9.2009/os/\$basearch/|g' /etc/yum.repos.d/CentOS-Base.repo sed -i "s/^mirrorlist=/#mirrorlist=/g" /etc/yum.repos.d/CentOS-Base.repo yum clean all yum makecache yum repolist