环境：centos7
创建的开机启动的链接地址：
/etc/systemd/system/multi-user.target.wants/
如：
[root@tiaobanji system]# ll /etc/systemd/system/multi-user.target.wants/
total 0
lrwxrwxrwx. 1 root root 38 Feb 28 12:18 auditd.service -> /usr/lib/systemd/system/auditd.service
lrwxrwxrwx. 1 root root 37 Feb 28 12:18 crond.service -> /usr/lib/systemd/system/crond.service
lrwxrwxrwx. 1 root root 42 Feb 28 12:18 irqbalance.service -> /usr/lib/systemd/system/irqbalance.service
lrwxrwxrwx. 1 root root 37 Feb 28 12:18 kdump.service -> /usr/lib/systemd/system/kdump.service
lrwxrwxrwx. 1 root root 46 Feb 28 12:18 NetworkManager.service -> /usr/lib/systemd/system/NetworkManager.service
lrwxrwxrwx 1 root root 37 Mar 6 17:37 nginx.service -> /usr/lib/systemd/system/nginx.service
lrwxrwxrwx. 1 root root 39 Feb 28 12:18 postfix.service -> /usr/lib/systemd/system/postfix.service
lrwxrwxrwx. 1 root root 40 Feb 28 12:18 remote-fs.target -> /usr/lib/systemd/system/remote-fs.target
lrwxrwxrwx. 1 root root 39 Feb 28 12:18 rsyslog.service -> /usr/lib/systemd/system/rsyslog.service
lrwxrwxrwx. 1 root root 36 Feb 28 12:18 sshd.service -> /usr/lib/systemd/system/sshd.service
lrwxrwxrwx. 1 root root 37 Feb 28 12:18 tuned.service -> /usr/lib/systemd/system/tuned.service
实际的开机服务地址：
/usr/lib/systemd/system
添加完实际的开机服务后需要执行：
systemctl daemon-reload