CentOS6升级到CentOS6CR

CentOS官方发布了CR升级库，这表明CentOS 6.1的发布可能又要延期了。

1. 安装yum配置文件：yum install centos-release-cr，官方的镜像不大稳定，建议使用mirrors.163.com。
   # CentOS-CR.repo
   #
   # The continuous release  ( CR ) repository contains rpms from the
   # next point release of CentOS, which isnt itself released as yet.
   #
   # Look at http://wiki.centos.org/AdditionalResources/Repositories/CR
   # for more details about how this repository works and what users 
   # should expect to see included / excluded
   
   
   [cr]
   name=CentOS-$releasever - CR
   baseurl=http://mirrors.163.com/centos/$releasever/cr/$basearch/
   gpgcheck=1
   enabled=1
   gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6
   
2. yum update 就发现很多更新可以下载。