centos7配置DNS

配置dns
https://blog.csdn.net/teisite/article/details/81196244

剛纔安裝smb時遇到問題yum [Errno 256] No more mirrors to try 解決方法：

系統信息：CentOS release 6.6 (Final)

1.yum clean all
2.yum makecache
3.yum update