Changing Hostname without rebooting the Server

Here the steps for changing the hostname in Linux without rebooting the server.

First you need to find out your current hostname:

# hostname
server1.kkdomain.com

Now, Edit /etc/hosts

For example, I need to assign it hostname as ftpsrv.mydomain.com. 

To do this, I have edited /etc/hosts as follows.# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 localhost.localdomain localhost
192.168.2.100 host.kkdomain.com host


Edit /etc/sysconfig/network

To change servers hostname to host.kkdomain.com, change the file as follows.

# cat /etc/sysconfig/network


NETWORKING=yes
HOSTNAME=host.kkdomain.com 
Now Type the following command in Terminal, 

# hostname host.kkdomain.com


#service syslog restart

Now, You should logout and login back to see the changes