1.备份本地源

mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo_bak

源的路径为: /etc/yum.repos.d/CentOS-Base.repo

2.获取阿里yum源配置文件

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

如果没有wget 就 yum install wget

no wget

如果下载不了就使用下面的命令:

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

3.更新yum缓存

yum makecache

4.查看当前yum源

yum repolist