centos7 修改yum源为阿里源

cd /etc/yum.repos.d

sudo mv CentOS-Base.repo CentOS-Base.repo.bak

sudo wget -O CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo[/code] 
4、安装epel repo源：

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


5、清理缓存

yum clean all


6、重新生成缓存

yum makecache