问题：
[root@cddserver2 ~]# yum -y install gcc-*
Loaded plugins: fastestmirror, presto
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=6&arch=x86_64&repo=os error was
14: PYCURL ERROR 6 - "Couldn't resolve host 'mirrorlist.centos.org'"
Error: Cannot retrieve repository metadata (repomd.xml) for repository: base. Please verify its path and try again
原因：
dns服务器没有配置正确
解决办法：
1、打开文件/etc/resolv.conf在其中添加：
nameserver 8.8.8.8
nameserver 8.8.4.4
search localdomain
2、然后重启网卡：使用命令: service network restart
关于：centOS 7 设置DNS方法 同之前版本不同
https://www.cnblogs.com/waw/p/10647074.html