1. sudo vi /etc/yum.repos.d/CentOS-Base.repo
2.将里边文件替换(insert %d 清除所有内容)
[base]
name=CentOS-$releasever - Base - Aliyun
baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-$releasever - Updates - Aliyun
baseurl=http://mirrors.aliyun.com/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras - Aliyun
baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus - Aliyun
baseurl=http://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
3. 保存退出, 清除yum缓存, 并重新加载仓库信息
sudo yum clean all
sudo yum makecache