1、备份配置文件
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
2、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
或者
curl -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
或者
curl -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
或者
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
点解这里查看更多-->https://opsx.alibaba.com/mirror
3、之后运行yum makecache生成缓存
yum makecache
1、在CentOS6和CentOS7都可以执行下面的命令安装epel仓库
yum -y install epel-release
2、 移除epel仓库
在CentOS6和CentOS7都可以执行下面的命令移除epel仓库
yum -y remove epel-release
3 、查看仓库信息
yum repolist
原文：https://www.cnblogs.com/wutao666/p/9534649.html