Which host name to put in /etc/hostname?

Solution 1:

You're specifying the name of the server, literally. Pick the one that you want your server to be, it's up to you.

It will be the default name for any services you run on the server unless you specify otherwise. For example, this is often going to be the default host to remotely connect to the server to such as with SSH. Nevertheless, many other protocols will be specified to utilize hostnames outside of your server's hostname. For example, rarely will Apache's primary role be to serve files on the server's default hostname.

With Debian, /etc/hostname is read by the /etc/init.d/hostname.sh init script and will reflect any changes upon reboot. To change dynamically without reboot, you can also run the command hostname $NEWHOSTNAME.

Solution 2:

You can call your server as you want, this doesn't need to have any relationship to the services or web sites it's hosting. This is particularly true if it's hosting multiple web sites.