cd /etc/yum.repos.d/
mkdir repo_bak
mv *.repo repo_bak/
wget http://mirrors.aliyun.com/repo/Centos-7.repo
wget http://mirrors.163.com/.help/CentOS7-base-163.repo
ll
pwd
yum clean all
yum makecache
yum list | grep epel-release
yum install -y epel-release
wget -O /etc/yum.repos.d/epel-7.repo http://mirrors.aliyun.com/repo/epel-7.repo
yum clean all
yum makecache
yum -y install rsync
原文连接：CentOS7系统配置国内yum源和epel源 - flytoyou - 博客园
