Rename unix hostname

Want to rename the hostname of a unix host.

Current name:     wagga01.example1111.com
New Name:         wagga01.example.com

Make sure that the HOSTNAME entry under /etc/sysconfig/network is updated to new name and reboot the machine and it is done.

Steps are below:

[root@wagga01 ~]# cat /etc/hosts
10.0.2.15       wagga01.example1111.com wagga01 # Added by NetworkManager
127.0.0.1       localhost.localdomain   localhost
::1     wagga01.example1111.com wagga01 localhost6.localdomain6 localhost6
[root@wagga01 ~]#
[root@wagga01 ~]#
[root@wagga01 ~]# cat /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=wagga01.example1111.com
[root@wagga01 ~]#
[root@wagga01 ~]#
[root@wagga01 ~]# hostname
wagga01.example1111.com
[root@wagga01 ~]#
[root@wagga01 ~]#
[root@wagga01 ~]# cat  /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=wagga01.example.com
[root@wagga01 ~]#
[root@wagga01 ~]#
[root@wagga01 ~]# hostname
wagga01.example1111.com
[root@wagga01 ~]#

[root@wagga01 ~]# shutdown -r now

[root@wagga01 ~]# hostname
wagga01.example.com
[root@wagga01 ~]#
[root@wagga01 ~]#
[root@wagga01 ~]# cat /etc/hosts
10.0.2.15       wagga01.example.com     wagga01 # Added by NetworkManager
127.0.0.1       localhost.localdomain   localhost
::1     wagga01.example.com     wagga01 localhost6.localdomain6 localhost6
[root@wagga01 ~]#
[root@wagga01 ~]#
[root@wagga01 ~]# cat /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=wagga01.example.com
[root@wagga01 ~]#

In case you are on centos or redhat then there is an easy way that is

# hostnamectl set-hostname wagga01.example.com

Then reboot:

# shutdown -r now