备份自带repo

  1. mkdir /etc/yum.repos.d/bak
  2. mv /etc/yum.repos.d/* /etc/yum.repos.d/bak

下载阿里云源

  1. curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

替换版本

  1. sed -i "s/\$releasever/7/g" /etc/yum.repos.d/CentOS-Base.repo

更新yum源

  1. yum clean all
  2. yum makecache