[kikinovak@calimero ~]$ cat /etc/hosts
127.0.0.1 calimero.local calimero localhost.localdomain localhost
[kikinovak@calimero ~]$ hostname calimero.local [kikinovak@calimero ~]$ hostname --fqdn calimero.local
Wouldn't this be more correct?
I would suggest not making 'local' part of your server name. Although localhost.localdomain, in a non network setting, can work absolutely fine, there is an issue with your email headers. The use of locahost, local, and stuff like that is a big red flag.
I changed, in my centos 5 server, where the host name was localhost.locadomain...
/etc/sysconfig/network Hostname=server1.mydomain.com (where the domain is one of my websites on the server, actually my name server too)
Change, for sendmail to work with it, the file local-hosts-names Add the new name to it Server1.mydomain.com
Change /etc/hosts First of all, leave all the original stuff and do not alter. Underneath the original stuff, just add <ipaddress> server1.mydomain.com
REBOOT
Then do this...
shell prompt> uname -n server1.mydomain.com
shell prompt> hostname -s Server1
shell prompt> hostname -d Mydomain.com
shell prompt> hostname -f server1.mydomain.com
shell prompt> hostname server1.mydomain.com
All of these steps allows the mail headers, at least in sendmail, to function properly. Other than that, unless you are in a network, or if you are not sending mail, it is usually not a biggie if you miss some steps.
This is what I did to resolve a new hostname.