服务管理工具:
- service
- /etc/init.d/network
- systemctl
- /usr/lib/systemd/system/
- sshd.service
- /usr/lib/systemd/system/
init 0 - 6
0:关机
1:单用户
init 3 :字符终端多用户模式
6:重启
chkconfig --list
systemctl start | stop | restart| reload|enable| disable 服务名称
软件包
/lib/systemd/system
.target 级别
systemctl get-default
systemctl set-default multi-user.target