Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; 未知的错误"

方法一：

[root@localhost yum.repos.d]# cat /etc/resolv.conf
nameserver 8.8.8.8

方法二：

[root@localhost network-scripts]# cat ifcfg-eth0 
###
ONBOOT=yes
###