How to Change your Hostname without Rebooting in RedHat Linux
This tutorial covers changing your hostname in RedHat Linux without having to do a reboot for the changes to take effect. I’ve tested this on RedHat 7.3, 9, Fedora Core 3, and CentOS 4.1. It should work for all the versions in between since they all closely follow the same RedHat configuration. What’s the point of this tutorial? Never reboot if you don’t have to and keep your uptime intact.
Make sure you are logged in as root and move to /etc/sysconfig and open the network file in vi.
cd /etc/sysconfig vi network
Look for the HOSTNAME line and replace it with the new hostname you want to use. In this example I want to replace localhost with redhat9.
When you are done, save your changes and exit vi. Next we will edit the /etc/hosts file and set the new hostname.
In hosts, edit the line that has the old hostname and replace it with your new one.
Save your changes and exit vi. The changes to /etc/hosts and /etc/sysconfig/network are necessary to make your changes persistent (in the event of an unscheduled reboot).
Now we use the
program to change the hostname that is currently set.
And run it again without any parameters to see if the hostname changed.
Finally we will restart the network to apply the changes we made to /etc/hosts and /etc/sysconfig/network.
service network restart
To verify the hostname has been fully changed, logout of your system and you should see your new hostname being used at the login prompt and after you’ve logged back in.