运行时sudo service apache2 reload，我收到错误：
apache2.service is not active, cannot reload
输出 sudo service apache2 status
root@gamma:~# sudo service apache2 status
? apache2.service - LSB: Apache2 web server
Loaded: loaded (/etc/init.d/apache2; bad; vendor preset: enabled)
Drop-In: /lib/systemd/system/apache2.service.d
??apache2-systemd.conf
Active: inactive (dead) since Sat 2016-10-15 08:23:11 UTC; 2h 28min ago
Docs: man:systemd-sysv-generator(8)
Process: 2203 ExecStop=/etc/init.d/apache2 stop (code=exited, status=0/SUCCESS)
Process: 2185 ExecStart=/etc/init.d/apache2 start (code=exited, status=0/SUCCESS)
Oct 15 08:23:10 gamma systemd[1]: Starting LSB: Apache2 web server...
Oct 15 08:23:10 gamma apache2[2185]: * …