1. 首先备份
sudo mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
2. 使用阿里云的源
sudo wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
3. 生成缓存
yum clean all yum makecache
1. 首先备份
sudo mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
2. 使用阿里云的源
sudo wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
3. 生成缓存
yum clean all yum makecache
原文：https://www.cnblogs.com/eagle6688/p/8297438.html