将Centos的yum源更换为国内的阿里云源

第一步：备份你的原镜像文件，以避免出错后能够恢复。
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup

 

第二步：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

第三步：运行yum makecache生成缓存
yum clean all
yum makecache