A hostname is basically your computer’s name by which it is recognized on the network. The hostname should be unique to avoid conflicts.
When you install Debian, you are asked to create a user name and a computer name. That is the hostname of your system,
The easiest way to know the hostname of your system is to open a terminal on the system or log in via SSH on the remote Linux system.
In terminal, you’ll notice that the prompt is usually in the fashion of user_name@hostname.
If it doesn’t show you that, you can always use the hostname command:
Now that you know your computer’s name and don’t like it, you can change it easily. In this tutorial, I’ll show you several ways of changing hostname of a Debian system.
Change hostname in Debian
I am going to show you two command line ways of changing the hostname in Debian Linux. The method should work on both Debian 9 and Debian 10.
Method 1: Use systemd for changing hostname in Debian
The first and preferred method for changing the hostname in Debian is to use the systemd command hostnamectl.
It’s a simple, single command and you don’t even need to restart your system for the changes to be taken in affect.
hostnamectl set-hostname new_hostname
Once you have done this, verify that the hostname change has been successful with the hostname or hostnamectl command:
hostnamectl Static hostname: raspberrypi Icon name: computer Machine ID: 0035faf761f945b8923fc7d54632a941 Boot ID: c487a76d67a34fd28a5f608aff19281c Operating System: Raspbian GNU/Linux 10 (buster) Kernel: Linux 4.19.29-v7l+ Architecture: arm
Exit the shell to see that yourname@hostname displays the new hostame.
Method 2: Change hostname in Debian using /etc/hosts
The etc directory in Linux contains the various configuration files. A couple of them relate to hostname. You can modify these files to change the hostname of your system.
First, use a command line text editor like Emacs or Vim to edit this file:
You’ll find just the old hostname here. Delete it and replace it with the new hostname.
It’s not done yet. You have to modify one more file. Go to /etc/hosts file and edit it. Here, replace your old hostname with the new one.
127.0.0.1 localhost 127.0.0.1 new_hostname # The following lines are desirable for IPv6 capable hosts ::1 ip6-localhost ip6-loopback fe00::0 ip6-localnet ff00::0 ip6-mcastprefix ff02::1 ip6-allnodes ff02::2 ip6-allrouters ff02::3 ip6-allhosts
Save and close the file and then verify it using the hostname or hostnamectl command. That’s it. If you won’t do this step, you’ll encounter “sudo: unable to resolve host” warning message every time you run sudo.
So, you just learn to change the hostname of your Debian server. Personally, I prefer the first method because it’s less of a hassle. How about you? Which method of changing hostname would you prefer?