1、备份

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 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

3、之后运行yum makecache生成缓存。

4、配置epol源。安装阿里云的epol源

a、备份(如有配置其他epel源)

mv /etc/yum.repos.d/epel.repo /etc/yum.repos.d/epel.repo.backup

mv /etc/yum.repos.d/epel-testing.repo /etc/yum.repos.d/epel-testing.repo.backup

2、下载新repo 到/etc/yum.repos.d/

epel(RHEL 7)

wget-O/etc/yum.repos.d/epel.repohttp://mirrors.aliyun.com/repo/epel-7.repo

epel(RHEL 6)

wget-O/etc/yum.repos.d/epel.repohttp://mirrors.aliyun.com/repo/epel-6.repo