 
yum install rpm -ivh 编译安装 三部曲:./configure make make install 卸载 rpm -e
通过ping 命令测试是否联网
#https://opsx.alibaba.com/mirror 来源
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
1.更改系统的yum源
#阿里云 mirrors.aliyun.com 
https://opsx.alibaba.com/mirror
#清华 
https://mirrors.tuna.tsinghua.edu.cn/help/centos/
#网易 
http://mirrors.163.com/.help/centos.html
yum install -y tree bash-completion wget vim # bash-completion命令 参数补全工具 wget 相当于迅雷一样 #vim类似 notepad++
2.关闭SElinux 
rpm -qa 
 #-qa query all 
 rpm -qa 
1#永久 修改配置文件 重启服务器之后生效
#     enforcing 	- 已开启 正在运行 
#     permissive 	- selinux关闭 警告提示
#     disabled 		- 彻底关闭
systemctl 管理服务
如何关闭防火墙
systemctl  stop     firewalld
systemctl  disable  firewalld
getenforce
systemctl  status       firewalld
systemctl  is-active    firewalld
systemctl  is-enabled   firewalld
systemctl enable firewalld.service
[root@oldboyedu-s8 ~]# rpm -qa   cronie
cronie-1.4.11-17.el7.x86_64
[root@oldboyedu-s8 ~]# systemctl is-active crond.service 
active
[root@oldboyedu-s8 ~]# systemctl is-enabled crond.service 
enabled
原文:https://www.cnblogs.com/zjchao/p/8955031.html