【VMware】CentOS6.5 Loaded plugins: fastestmirror, refresh-packagekit, security Loading mirror speeds

最近在用Centos 6.5 的时候出现了这种情况，

[root@bogon Desktop]# yum -y install docker
Loaded plugins: fastestmirror, refresh-packagekit, security
Loading mirror speeds from cached hostfile
	* base: mirrors.aliyun.com
	* extras: mirrors.nwsuaf.edu.cn
	* updates: mirrors.huaweicloud.com
http://mirrors.aliyun.com/centos/6.8/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 6 - "Couldn't resolve host 'mirrors.aliyun.com'"
Trying other mirror.
http://centos.ustc.edu.cn/centos/6.8/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.neusoft.edu.cn/centos/6.8/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 6 - "Couldn't resolve host 'mirrors.neusoft.edu.cn'"
Trying other mirror.

遇到这种情况有两种做法：

1、没网，试着：ping www.baidu.com 如果显示没有连接的话，就说明没网，也就无法使用yum 命令。
2、ping通了的话，还是是用不了yum命令，说明是yum镜像没有了，那么就得下载一个来更新。

在安装完CentOS后一般需要修改yum源，才能够在安装更新rpm包时获得比较理想的速度。
国内比较快的有163源、sohu源。这里以163源为例子。

# cd /etc/yum.repos.d

# mv CentOS-Base.repo CentOS-Base.repo.backup

# wget http://mirrors.163.com/.help/CentOS6-Base-163.repo

# mv CentOS6-Base-163.repo CentOS-Base.repo

# yum clean all

最后在使用yum 就可以了