Change a server's hostname in CentOS

network

Using a text editor, open the server’s /etc/sysconfig/network file.

$ sudo vi /etc/sysconfig/network
# Modify the HOSTNAME= value to match your FQDN hostname.

HOSTNAME=myserver.domain.com

For internal networking, change the host that is associated with the main IP address for your server (found at /etc/hosts).

127.0.0.1      localhost localhost.localdomain

123.45.67.89   hostname.domain.com   hostname

-- INSERT --                         2,43-57    ALL
Run the hostname command. This command lets you change the hostname on the server that the command line remembers, but it does not actively update all programs that are running under the old hostname.

[root@host ~]# hostname hostname.domain.com

[root@host ~]# hostname

Returns:
hostname.domain.com

[root@host ~]#
Restart networking on your server to ensure that changes will persist on restart.

$ /etc/init.d/network restart