HowTo Set RHEL7 Hostname

Overview

This HowTo will provide some information about the different types of hostnames and how to set them in RHEL7 (Redhat 7 or CentOS 7) based machine. If you have built your new RHEL7 based machine and have now got a bit stuck over how to change the hostname from localhost.localdomain to what ever you want this is the how to for you.

Types Of Hostnames

There are three types of hostnames: Static, Pretty and Transient.

Static Hostname

The Static hostname is essentially the traditional hostname which is stored in the “/etc/hostname” file.

[user@server ~]$ cat /etc/hostname
server.example.com

Transient Hostname

The Transient hostname is a dynamic hostname which is maintained at a kernel level. It is initialized by the static hostname, but can be changed by DHCP and other network services.

Pretty Hostname

The Pretty hostname is a free form hostname for presentation to the user.

Set The Hostname

The hostname can be changed by editing the “/etc/hostname” file or with the hostnamectl command.

[root@server ~]# hostnamectl set-hostname server-test.example.com

This command will set all three hostnames at the same time, but all three can be set individually using the “-static”, “-transient” or “-pretty” flags.

Validate “/etc/hostname” has been updated

[root@server ~]# cat /etc/hostname
server-test.example.com

Hostname Information

You can see a bit of information with the hostnamectl command which is very useful. man hostnamectl

[root@server ~]# hostnamectl
   Static hostname: server.domain.tld
         Icon name: computer-vm
           Chassis: vm
        Machine ID: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
           Boot ID: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
    Virtualization: vmware
  Operating System: CentOS Linux 7 (Core)
       CPE OS Name: cpe:/o:centos:centos:7
            Kernel: Linux 3.10.0-123.4.4.el7.x86_64
      Architecture: x86_64