Introduction
In certain circomstances, a host needs to know its fully qualified
domain name (FQDN). It tries to find out what name is associated
with the IP address 127.0.0.1. This is not set in the DNS but
on the local machine.
The /etc/hostname file
First you should check the hostname file
root@server:~# cat /etc/hostname␍
root@server:~# server
If you get something diffrent
root@server:~# nano /etc/hostname␍
and make sure you have server followed by a newline. Force a change in the hostname by
root@server:~# hostname -f /etc/hostname␍
This will not set the FQDN, for that you need /etc/hosts
The /etc/hosts file
Look at /etc/hosts.
root@server:~# nano /etc/hosts
This file should, at the top, contain two lines that look as follows.
127.0.0.1 localhost
127.0.0.1 server.openlib.org server
Use
root@server:~# nano /etc/hosts
to make sure you have the two lines there. You can test your setting by
root@server:~# hostname␍
root@server:~# server
root@server:~# hostname -f␍
root@server:~# server.openlib.org
This is the correct setup, if you don't see this something is wrong.