准备工作

检查wget是否安装

wget -V

安装

yum install wget -y

1、备份原有yum源

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

2、选择可用的yum源

阿里云

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

163

wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.163.com/.help/CentOS7-Base-163.repo

3、生成缓存

yum clean all  # 清除yum缓存
yum makecache  # 重建缓存
yum -y update  # 升级所有包