Repodata is over 2 weeks old. Install yum-cron? Or run: yum makecache fast

Repodata is over 2 weeks old. Install yum-cron? Or run: yum makecache fast
的解决方法：

在命令行输入：yum clean all

http://www.cnblogs.com/lilei9110/p/4335967.html