You may see the follwing message on Deki VM (8.05.1 I used), and Apache can't start.
dekiwiki:/etc/apache2# /etc/init.d/apache2 start
* Starting web server (apache2)...
apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.0.1 for ServerName
...done.
You can consider to move "localhost" entry after "dekiwiki" as described below, in /etc/hosts file.
dekiwiki:/etc/apache2# vi /etc/hosts
#127.0.0.1 localhost
127.0.0.1 dekiwiki.localdomain dekiwiki localhost
Then Apache2 can start, in my case.
dekiwiki:/etc/apache2# /etc/init.d/apache2 start
* Starting web server (apache2)...
...done.