配置fastDfs时的坑：CentOs7上重启防火墙报Unit

配置fastDfs时的坑：CentOs7上重启防火墙报

Unit not found

或者

Job for iptables.service failed because the control process exited with error 
code. See "systemctl status iptables.service" and "journalctl -xe" for details.

参考博客：

CentOs7与CentOs6的差异问题https://www.cnblogs.com/faunjoe88/p/7003815.html

centos7默认的防火墙是firewalld防火墙，不是使用iptables，所以要先关闭firewalld，再开启iptables
https://blog.csdn.net/sinat_29821865/article/details/80982250