国内版，国内服务器使用 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 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、之后运行yum makecache生成缓存


海外版，海外服务器可使用

sed -i -r -e 's|^mirrorlist=|#mirrorlist=|g' -e 's|^#?baseurl=http://mirror.centos.org/centos|baseurl=https://vault.centos.org/centos|g' -e 's|^#?baseurl=http://mirror.centos.org/altarch|baseurl=https://vault.centos.org/altarch|g' -e 's|^#?baseurl=http://download.fedoraproject.org|baseurl=http://download.fedoraproject.org|g' /etc/yum.repos.d/CentOS-*.repo  && yum clean all && yum makecache