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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