Commands to Configure hostname on CentOS 7 and RHEL 7

On my Slackware boxes, I just put the hostname in /etc/HOSTNAME and /etc/hosts. No 'hostnamectl' nonsense here.

One more reason that I'm happy to keep my servers on CentOS 6, no hostnamectl nonsense there either.

> I just put the hostname in /etc/HOSTNAME and /etc/hosts.

Does that change the current name, or does it only take effect when the machine is rebooted? I was under the impression you had to use the hostname command to change the current name. But I've never had to change the hostname on a running machine, so I'm not certain.

@jdixon:

You are correct.

$man hostname

/etc/hostname Historically this file was supposed to only contain the hostname and not the full canonical FQDN. Nowadays most software is able to cope with a full FQDN here. This file is read at boot time by the system initialization scripts to set the hostname.

I just used hostnamectl to change that name 2 days ago and did not reboot. No problem until now. That doesn't seem a nonsense utility. Is it because it's a systemd tool ?

> just used hostnamectl to change that name 2 days ago and did not reboot.

You don't need to reboot if you use the hostname command either. It just that (for Slackware) if you only change /etc/HOSTNAME, it's only read on a reboot.