yum下载软件失败：‘Could not resolve host: mirrorlist .centos .org； Unknowm error

Loaded plugins: fastestmirror, ovl

Determining fastest mirrors

Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7\&arch=x86_64\&repo=os\&infra=container error was

14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error"

解决办法：

vi  /etc/yum/pluginconf.d/fastestmirror.conf  
plugins=0
vi /etc/yum.conf
enabled=0
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
yum clean all
yum update