yum doesn‘t have enough cached data to continue.

1.备份原有yum源：

mv /etc/yum.repos.d /etc/yum.repos.d.bak

2.创建yum源目录

mkdir /etc/yum.repos.d

3.下载阿里云yum源配置

wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

4.重建yum缓存

yum clean all
yum makecache