Commands to Configure hostname on CentOS 7 and RHEL 7

http://www.linuxtechi.com/configure-hostname-on-centos-7-and-rhel-7

Hostname is defined as label or name of a computer and network device. In this article we will discuss how to set and modify hostname on CentOS 7 & RHEL 7. There are three different commands through which we can query, set and modify hostname.

• hostnamectl
• nmtui
• nmcli

Types of Hostname that we can set on CentOS 7 and RHEL 7 server.

• Static Hostname — It is conventional hostname that we set on the servers and as the name suggest hostname will be static and persistent accross the reboot.Static hostname is stored in the file /etc/hostname.
•  Transient Hostname — It is the hostname which is obtained from DHCP and mDNS. Transient hostname might be temporary because it is only temporarily written to kernel hostname.
•  Pretty Hostname — It is a hostname that can include all kind of special characters. Pretty hostname is stored in the file /etc/machine-info .

Commands to check the hostname :

[root@localhost ~]# hostname
OR
[root@localhost ~]# hostnamectl status
OR
[root@localhost ~]# hostnamectl

hostnamectl command :

hostnamectl command is used to configure,modify and query hostname. Basic syntax is listed below :
# hostnamectl
Let’s set the static hostname ‘cloud.linuxtechi.com‘

[root@localhost ~]# hostnamectl set-hostname "cloud.linuxtechi.com"
[root@localhost ~]#

Verify the new hostname using hostnamectl and hostname command :

Remove or clear the hostname (cloud.linuxtechi.com)

[root@cloud ~]# hostnamectl set-hostname ""
[root@cloud ~]# 
[root@cloud ~]# hostname
localhost.localdomain
[root@cloud ~]# hostnamectl 
 Static hostname: n/a
Transient hostname: localhost
 Icon name: computer
 Chassis: n/a
 Machine ID: a5c10f2a26324894a3b0b83d504c1ff2
 Boot ID: c3ff9d084b364b56bb0d588b64ff6f1a
 Virtualization: oracle
 Operating System: CentOS Linux 7 (Core)
 CPE OS Name: cpe:/o:centos:centos:7
 Kernel: Linux 3.10.0-123.el7.x86_64
 Architecture: x86_64
[root@cloud ~]#

Set Pretty Hostname :

[root@cloud ~]# hostnamectl set-hostname "Pradeep Antil's CentOS-7 Laptop" --pretty
[root@cloud ~]#

Remove Pretty hostname :

[root@cloud ~]# hostnamectl set-hostname "" --pretty

Set Hostname on the Remote Server from your local machine.
Syntax :
# hostnamectl set-hostname -H @
Above command will use ssh for connecting and authentication for remote server.

root@linuxworld:~# hostnamectl set-hostname -H 192.168.1.13 @cloud.linuxtechi.com
root@192.168.1.13's password:
root@linuxworld:~#

nmtui command :

[root@cloud ~]# nmtui

Restart the hostnamed service

[root@cloud ~]# systemctl restart systemd-hostnamed
[root@cloud ~]#

Verify new hostname using ‘hostname’ & ‘hostnamectl’ command

nmcli command :

nmcli is a command line utility for configuring and query hostname.
Check the hostname :

[root@cloud ~]# nmcli general hostname
cloud.linuxtechi.com
[root@cloud ~]#

Change the hostname :
Syntax :
# nmcli general hostname

[root@cloud ~]# nmcli general hostname antil.linuxtechi.com

Restart the hostnamed service using below systemctl command

[root@cloud ~]# systemctl restart systemd-hostnamed
[root@cloud ~]# hostname
antil.linuxtechi.com
[root@cloud ~]#

Note :hostnamectl command is recommended to query and configure hostname.