通常、次のようなメッセージが表示されます。
Job for apache2.service failed because the control process exited with error code.
See "systemctl status apache2.service" and "journalctl -xe" for details.
だからあなたがする必要があるのは実行することです:
journalctl -xe
次に、次のような出力が表示されます
Nov 16 03:27:26 naboo sudo[9909]: pam_unix(sudo:session): session opened f
Nov 16 03:27:28 naboo systemd[1]: Starting The Apache HTTP Server...
-- Subject: Unit apache2.service has begun start-up
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- Unit apache2.service has begun starting up.
Nov 16 03:27:29 naboo apachectl[9939]: (98)Address already in use: AH00072
Nov 16 03:27:29 naboo apachectl[9939]: no listening sockets available, shu
Nov 16 03:27:29 naboo apachectl[9939]: AH00015: Unable to open logs
Nov 16 03:27:29 naboo apachectl[9939]: Action 'start' failed.
Nov 16 03:27:29 naboo apachectl[9939]: The Apache error log may have more
Nov 16 03:27:29 naboo systemd[1]: apache2.service: Control process exited,
Nov 16 03:27:29 naboo systemd[1]: apache2.service: Failed with result 'exi
Nov 16 03:27:29 naboo systemd[1]: Failed to start The Apache HTTP Server.
-- Subject: Unit apache2.service has failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- Unit apache2.service has failed.
--
-- The result is RESULT.
Nov 16 03:27:29 naboo sudo[9909]: pam_unix(sudo:session): session closed f