由于安装了resolvconf包，开机自动覆盖resolv.conf.

找到 “/etc/resolvconf/resolv.conf.d/”:
base – 空
head
original – 空
tail – 空
vim /etc/resolvconf/resolv.conf.d/head

OpenDNS

nameserver 219.141.136.10
nameserver 219.150.32.132