Centos: How to Set Hostname in Centos

Setting the hostname in CentOS (RHEL).

Sometimes during setup of your CentOS system you forget to set the hostname of the server, or you may get situations where you need to change the hostname. This quick tutorial will show you just how easy it is to do this.

Firstly, check the current hostname by entering the command:

# hostname
localhost.localdomain


You can also check hostname by issuing following command:

# sysctl kernel.hostname
kernel.hostname = localhost.localdomain


You can temporarily change hostname by issuing following command, but upon reboot, it will revert to it's previous setting

# hostname myservername.domain.com


While this temporary change maybe useful for troubleshooting, to make it permanent, just change the following network file at /etc/sysconfig/network

vi /etc/sysconfig/network


It will look something like:

NETWORKING=yes
HOSTNAME=localhost.localdomain

Hit "i" to insert and change the HOSTNAME value to your FQDN, such as myservername.domain.com

NETWORKING=yes
HOSTNAME=myservername.domain.com

Hit Escape, then :wq to save and exit.

Check that the hostname is now set:

# hostname
myservername.domain.com
# sysctl kernel.hostname
kernel.hostname = myservername.domain.com


Finally, log out and back in using a new session and you'll see you're now logged on as root@myservername

To properly check, reboot your server to see that the change is now permanent.