Linux setting hostname and domain name of my server

I would like to change hostname and domain name for my Linux server. Where can I set the local hostname and domain name of my server?

You can use hostname/hostnamectl command to show or set the system’s host name and dnsdomainname command to show the system’s DNS domain name. But the changes are temporary if you use these commands. Local hostname and the domain name of your server defined in text configuration file located in /etc directory.

How to use hostnamectl command

If you are using systemd based distro such as RHEL/CentOS 7.x, Fedora latest, Ubuntu Linux 16.04 LTS, Debian 9.x+, Arch Linux and more, use hostnamectl command. To see current hostname, run:
$ hostnamectl
To change hostname to foo, run:
$ hostnamectl set-hostname 'foo'
$ hostnamectl

A note about GUI tools

If you are using Red Hat or Fedora Linux (older version) use redhat-config-network GUI tool. Type following command and click on DNS tab > Setup hostname and domain name:
# redhat-config-network
On other hand you can edit a text file. Find out and set up the value for HOSTNAME in the file /etc/sysconfig/network:
# vi /etc/sysconfig/network
Setup/replace HOSTNAME
HOSTNAME=web.nixcraft.com
Where, web is hostname and nixcraft.com is your DNS domain name.

If you are using Debian Linux

You need to edit /etc/hostname file and put hostname.domain.com in this file:
# vi /etc/hostname
Set or replace hostname:
web.nixcraft.com

Debian, Suse and other Linux distro support GUI tool called network-admin. Type following command and click on DNS tab > Setup hostname and domain name:
$ network-admin

Please note that you must have properly configured DNS server to work FQDN based hostname. See how to configure Linux as a dns client.

See also:

• Linux > Linux Setup DNS client
• List of LINUX troubleshooting commands/tools part # 1

Category	List of Unix and Linux commands
Disk space analyzers	ncdu • pydf
File Management	cat
Firewall	Alpine Awall • CentOS 8 • OpenSUSE • RHEL 8 • Ubuntu 16.04 • Ubuntu 18.04 • Ubuntu 20.04
Network Utilities	NetHogs • dig • host • ip • nmap
OpenVPN	CentOS 7 • CentOS 8 • Debian 10 • Debian 8/9 • Ubuntu 18.04 • Ubuntu 20.04
Package Manager	apk • apt
Processes Management	bg • chroot • cron • disown • fg • jobs • killall • kill • pidof • pstree • pwdx • time
Searching	grep • whereis • which
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WireGuard VPN	Alpine • CentOS 8 • Debian 10 • Firewall • Ubuntu 20.04