64bit
http://archive.kernel.org/centos-vault/6.8/isos/x86_64/CentOS-6.8-x86_64-bin-DVD1.iso
32bit
http://archive.kernel.org/centos-vault/6.8/isos/i386/CentOS-6.8-i386-bin-DVD1.iso
源配置
来自：http://mirrors.aliyun.com/help/centos
(备份)
sudo mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
(下载 CentOS-Base.repo 到 /etc/yum.repos.d)
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo(运行 yum makecache 生成缓存)