1.安装wget
yum install -y wget
2.完事前都做备份
cp /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
3.下载阿里云镜像文件
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
4.清理缓存
yum clean all
5.生成缓存
yum makecache
6.更新最新源设置
yum update -y
原文链接:https://blog.csdn.net/u014514528/java/article/details/101083047