使用yum-plugin-priorities工具实现
yum install -y yum-plugin-priorities
yum源配置文件(/etc/yum.repos.d/CentOS-Base.repo)添加priority=n的配置项,
n值越小越优先
[aliyun]
name=alirepo
baseurl=https://mirrors.aliyun.com/centos/$rele