将Centos的yum源更换为阿里云源

阿里云镜像源地址：http://mirrors.aliyun.com/

①备份原镜像源文件到原文件夹，便于恢复

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

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

③更改CentOS-Media.repo使其为不生效

enabled=0

④运行yum makecache生成缓存

yum clean all

yum makecache