错误描述：
[root@www php-fpm.d]# service nginx restart
Redirecting to /bin/systemctl restart nginx.service
Failed to restart nginx.service: Unit nginx.service failed to load: No such file
centos7.2环境下安装php5.6.17。
启动失败。
Job for php-fpm.service failed because the control process exited with error code. See "systemctl status php-fpm.service"
