配置网络yum源
阿里云镜像源站点（http://mirrors.aliyun.com/）
centos镜像参考：http://mirrors.aliyun.com/help/centos
下载新的CentOS-Base.repo 到/etc/yum.repos.d/
CentOS 5
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-5.repo
CentOS 6
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
CentOS 7
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
之后运行yum makecache生成缓存
配置epel源：
配置参考：http://mirrors.aliyun.com/help/epel
下载新repo 到/etc/yum.repos.d/
epel(RHEL 7)
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
epel(RHEL 6)
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-6.repo
epel(RHEL 5)
wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-5.repo
之后运行yum makecache生成缓存
来源：https://www.cnblogs.com/sixad/p/7124629.html