CentOS7 yum镜像改为阿里云

1、非阿里云ECS需要执行以下代码

sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo

2、备份原CentOS-Base.repo文件

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

3、使用wget下载新的 CentOS-Base.repo 到 /etc/yum.repos.d/

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

4、运行 yum makecache 生成缓存

如果提示wget command not found 则没有安装wget

yum install wget 即可

错误：can not find a valid baseurl for repo: base/7/x86-64

详见：CentOs7 linux yum命令执行can not find a valid baseurl for repo: base/7/x86-64