It seems that your primary objective is to get the most of your RAM for performance and not for holding bloated or unneeded software, right? if so, just disabling Apache (for instance) is enough; you don't get any benefit by uninstalling it.
Therefore, the best is to check ps fax output. You'll see every package running and how many subprocesses it's spawning. quite likely you're not running FTP, so you don't have to worry about that either.
Besides, most of the non-performance-critical services can run from inetd (or likely xinetd). In that case they're not holding any RAM until you access the right port.
In my experience, Ubuntu server (without LAMP) is very close to barebones. I usually just add ssh, nginx and whatever backserver i'm using.
If, on the other hand, you want to reduce disk usage, then you'll be better served by a different distro or (the best option, IMHO) Linux From Scratch
I would choose a consistent approach across the entire environment. Both solutions work fine and will remain compatible with most applications. There is a difference in manageability, though.
I go with the short name as the HOSTNAME setting, and set the FQDN as the first column in /etc/hosts for the server's IP, followed by the short name.
I have not encountered many software packages that enforce or display a preference between the two. I find the short name to be cleaner for some applications, specifically logging. Maybe I've been unlucky in seeing internal domains like server.northside.chicago.rizzomanufacturing.com. Who wants to see that in the logs or a shell prompt?
Sometimes, I'm involved in company acquisitions or restructuring where internal domains and/or subdomains change. I like using the short hostname in these cases because logging, kickstarts, printing, systems monitoring, etc. do not need full reconfiguration to account for the new domain names.
A typical RHEL/CentOS server setup for a server named "rizzo" with internal domain "ifp.com", would look like:
/etc/sysconfig/network:
HOSTNAME=rizzo
...
-
/etc/hosts:
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
172.16.100.13 rizzo.ifp.com rizzo
-
[root@rizzo ~]# hostname
rizzo
-
/var/log/messages snippet:
Dec 15 10:10:13 rizzo proftpd[19675]: 172.16.100.13 (::ffff:206.15.236.182[::ffff:206.15.236.182]) - Preparing to
chroot to directory '/app/upload/GREEK'
Dec 15 10:10:51 rizzo proftpd[20660]: 172.16.100.13 (::ffff:12.28.170.2[::ffff:12.28.170.2]) - FTP session opened.
Dec 15 10:10:51 rizzo proftpd[20660]: 172.16.100.13 (::ffff:12.28.170.2[::ffff:12.28.170.2]) - Preparing to chroot
to directory '/app/upload/ftp/SRRID'
Best Answer
From my experience, I've seen more CentOS and RHEL than anything else. Of course everyone is going to have their own opinion and preference but those would be my 2 picks.