Linux how to change hostname

How to change your hostname in Linux

Posted: March 3, 2020 |

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Your hostname is a vital piece of system information that you need to keep track of as a system administrator. Hostnames are the designations by which we separate systems into easily recognizable assets. This information is especially important to make a note of when working on a remotely managed system. I have experienced multiple instances of companies changing the hostnames or IPs of storage servers and then wondering why their data replication broke. There are many ways to change your hostname in Linux; however, in this article, I’ll focus on changing your name as viewed by the network (specifically in Red Hat Enterprise Linux and Fedora).

Background

Modern Linux systems have three different types of hostnames configured. To minimize confusion, I list them here and provide basic information on each as well as a personal best practice:

It is recommended to pick a pretty hostname that is unique and not easily confused with other systems. Allow the transient and static names to be variations on the pretty, and you will be good to go in most circumstances.

Working with hostnames

Before moving on from the hostname command, I’ll show you how to use it to change your transient hostname. Using hostname (where x is the new hostname), you can change your network name quickly, but be careful. I once changed the hostname of a customer’s server by accident while trying to view it. That was a small but painful error that I overlooked for several hours. You can see that process below:

It is also possible to use the hostnamectl command to change your hostname. This command, in conjunction with the right flags, can be used to alter all three types of hostnames. As stated previously, for the purposes of this article, our focus is on the transient hostname. The command and its output look something like this:

The final method to look at is the sysctl command. This command allows you to change the kernel parameter for your transient name without having to reboot the system. That method looks something like this:

GNOME tip

Wrapping up

I hope that you found this information useful as a quick and easy way to manipulate your machine’s network-visible hostname. Remember to always be careful when changing system hostnames, especially in enterprise environments, and to document changes as they are made.

Want to try out Red Hat Enterprise Linux? Download it now for free.

How To Set Or Change Hostname On Linux

We already discussed how to view or find a Linux system’s hostname. In this brief guide, we will see how to set or change hostname in Linux, either temporarily or permanently.

What is Hostname?

A Hostname is an unique, alphanumeric label assigned to a Linux system to identify it on the network. A typical hostname can contain alphabets, numbers and a few special characters such as hyphen (-), period (.), and underscore (_). Generally, a hostname consist of up to 253 characters. Please note that a hostname should not start with a hyphen. In most Linux distributions, the hostname is stored in the /etc/hostname file.

The hostname is usually set while installing the OS. You can also set a new hostname or change the existing hostname after installing the OS, either from command line or from Settings section in graphical mode. First, we will see the CLI way to set Linux hostname.

1. Set Or Change Hostname On Linux From Commandline

Changing computer name in Linux is no big deal. We can set a Linux system’s name with a few one-liner commands.

The simplest and quickest way to change a Linux system’s hostname is:

This command sets the hostname as ostechnix. Please note that this command will only set the computer name temporarily. Once you reboot the system, the hostname will be reverted to old name. To permanently set hostname in Linux, use any one of the following methods.

There are many ways to permanently set or change Linux hostname from commandline. Here are a few methods:

1.1. Set Linux hostname with hostnamectl command

The hostnamectl command is used to display and change the system hostname and related settings in Linux systems.

Let us check the current hostname with command:

As you see in the above output, my Ubuntu system’s name is «ubuntuserver». Let us change it to ostechnixserver.

To set hostname in Linux with hostnamectl command, run:

Replace the «ostechnixserver» in the above example with your own name.

Log out and log back in to take effect the changes. If you are on SSH session, exit the session and reconnect it.

Now verify if the hostname has been changed or not with hostnamectl command:

Or display only the hostname:

Alternatively, you can use the hostname command:

1.2. Set Linux hostname with nmcli command

The nmcli is a commandline tool used to create, display, edit, delete, activate, and deactivate network
connections, as well as control and display network device status in Linux operating systems.

To set hostname in Linux with nmcli command, do:

Log out and log back in to apply the changes.

1.3. Change Linux hostname by editing /etc/hostname file

As mentioned already, the computer name is stored in /etc/hostname file in most Linux distributions.

Let us look at the contents of this file:

To change the Linux system’s hostname, edit /etc/hostname file with your favorite editor:

Replace old hostname with new hostname of your choice.

Save the file and close it. Log out and lag back in to take effect the changes.

Alternatively, use the following one-liner command to update the hostname in /etc/hostname file:

1.4. Change Linux hostname with sysctl command

To change hostname in Linux with sysctl command, run:

Replace «ostechnixserver» with your own hostname. Don’t forget to log off and log back in to apply the changes.

1.5. Change Linux hostname with ProcFs

Proc file system, or procfs in short, is a virtual file system maintained by the Linux kernel. It is also sometimes referred to as a process information pseudo-file system. It doesn’t contain ‘real’ files but runtime system information such as system memory, devices mounted, hardware configuration etc. All these information are available under a special directory named /proc in Linux.

If you want to update the hostname, just append the new hostname in /proc/sys/kernel/hostname file using command:

You need to log out and log back in to apply the changes.

2. Set Or Change Hostname On Linux From Graphical mode

This method is for any Linux distribution installed with GNOME desktop environment.

Open the Gnome Settings section from Dash.

How do I change the hostname without a restart?

I want to change the OS hostname but I do not want to restart.

I have edited /etc/hostname but it requires a restart to get implemented. How to avoid this?

14 Answers 14

It’s easy. Just click the Gear icon (located at upper right corner of the screen), open «About this computer» screen (located at Gear icon ) and edit «Device name».

Or, in a terminal, use the following command:

This will set the hostname to your-new-name until you restart. See man hostname and How do I change the computer name? for further information. Do not use _ in your name.

Note

After a restart your changes in /etc/hostname will be used, so (as you said in the question), you should still use

(or some other editor) so that file contains the hostname.

To test that the file is set up correctly, run:

You should also edit /etc/hosts and change the line which reads:

so that it now contains your new hostname. (This is required otherwise many commands will cease functioning.)

Ubuntu 13.04 onwards

The hostnamectl command is part of the default installation on both Desktop and Server editions.

Without Restart

Changing the hostname or computer name in ubuntu without restart

Edit /etc/hostname and change to the new value,

Edit /etc/hosts and change the old 127.0.1.1 line to your new hostname

Note : i have read it on a forum > Edit /etc/hosts and change the old 127.0.1.1 line to your new hostname (if you dont do this, you wont be able to use sudo anymore. If you hav e already done it, press ESC on the grub menu, choose recovery, and edit your host file to the correct settings)

Now after a reboot, your hostname will be the new one you chose

Without Reboot

To change without a reboot, you can just use hostname.sh after you edit /etc/hostname. You must keep both your host names in /etc/hosts (127.0.0.1 newhost oldhost) until you execute the command below:

Note : Above command to make the change active. The hostname saved in this file (/etc/hostname) will be preserved on system reboot (and will be set using the same service).

How to Set or Change Hostname in Linux? [Linux Change Hostname]

This blog post will help you to change hostname in Linux or Linux Hostname Change with an easy step by step guide for beginner

List of content you will read in this article:

To identify hosts or servers in a network, each Linux server is assigned a name called host-name. It’s simply a name given to your Linux machine. When you install any Linux distribution, it will ask you to enter a username and a hostname for the first time. At any point in time, if you wish to change the hostname for any purpose, you can easily do so in just a few steps. However, please note that you should never assign the same hostname to multiple Linux servers in the same network.

There are some rules when it comes to what name can you assign as a hostname to a server in the network. A hostname can contain digits, lowercase letters, hyphens, and dots. But please make sure that a hostname must start and end with either a number or a letter. They must contain at least 2 characters and at most 63 characters.

How to Display Current Linux Hostname with hostname command?

When you open a terminal, you will find the following structure at the beginning of every Linux terminal command.

To display the current hostname in the terminal, you can use the hostname command.

How to change Linux hostname for various Linux distros?

1. How to change hostname in Ubuntu/Debian-based Distros?

If you own a Debian-based Linux distribution such as Ubuntu, Linux-Mint, etc., you can use either a command-line method or a GUI-based method to change Linux hostname. We will discuss two methods to change hostname using the command line in this article.

Method 1. Using systemd tools

We can use systemd tools to change the hostname along with some other similar type of information. Let’s use the following command first to get the current information.

You can see information such as hostname, OS, kernel, Machine ID, Boot ID, etc.

We can use the following hostnamectl command to change your current username.

You can see that the static hostname has been changed successfully. If you restart your terminal, you will see the changes reflected there as well.

Method 2. Using hostname command with example

You can also use the hostname command to change your hostname in Debian-based Linux Distributions.

You will need Sudo privileges to use this command. Restart the terminal to see the changes. However, using this command, the changes will be made temporarily. This means that once you restart your machine, the old hostname will be restored.

If you want to change your hostname permanently, you need to make the required changes in the following files — /etc/hostname and /etc/hosts. These are the two files where the Debian-based Linux distros stores information related to the hostnames. We can edit these files straight through the command line using editors such as vim and nano.

$ vi /etc/hostname
$ vi /etc/hosts

Once you have made changes to these files, it will be done permanently.

2. How to Change hostname in CentOS/RHEL 7 or 8?

If you use a Redhat-based Linux Distribution like CentOS, you can use the following three methods to change your hostname.

Method 1.

You can use the same hostnamectl command that we used for Debian-based Linux distributions to change the hostname in Redhat-based Linux distros as well. In fact, this command holds true for all Linux distros that use systemd.

First, let’s display the current hostname using any of the following commands.

The second command uses the -s option which tells the command to print only the short name or the hostname of the computer. The -f option will print the FQDN if it’s a part of a domain. The next command will print the contents of the hostname file which stores the hostname of the Linux machine. We can additionally use the hostnamectl command to print the hostname.

We can now use the following command to change the hostname in CentOs 7, 8, or any other Redhat-based Linux Distro.

Now, to apply these changes, just reboot the system using the following command.

Method 2.

You can also edit the file called /etc/hostname and write your new hostname on any CentOS machine.

Just reboot the system again to see the changes.

Method 3.

The Linux Kernel maintains a transient hostname as an auxiliary server name along with the conventional static hostname. We can use the Linux sysctl to change the transient hostname.

You can use the above command to display the current transient hostname.

The above commands can also be used to set a new hostname.

Wrapping Up!

In this comprehensive guide, we started with a basic introduction to discuss what are hostnames in Linux machines and what purpose do they serve. We also discussed a few methods that we can use to display the current hostname in Linux servers. We then discussed a general method that can be used to change the hostnames in any type of Linux Distribution whether Debian-based, RHEL-based, etc. We then discussed separate methods to change the hostnames in Debian-based distributions such as Ubuntu, Linux Mint, etc. We can also set the hostnames using a GUI-based method by moving to the user settings. We also discussed a few methods to change the hostname for RHEL-based distributions such as CentOS 7, 8, etc.

There might be several reasons why you would want to change Linux hostname of your device in a network. Regardless of all those reasons, changing Linux hostnames is quite easy and can be done in just a few steps only. We hope that this comprehensive guide serves its purpose and you can now change your hostnames easily. also if you are looking to buy a Linux server you can opt for MonoVM as the best Linux server provider.

How to Change the Hostname in Linux (Debian, Ubuntu, Arch, RedHat)

This article will show you how to change the hostname for your Linux device (Debian, Arch, Ubuntu, or RedHat).

The methods below should work for the vast majority of current and obsolete Linux Distributions.

What is the Hostname?

The hostname of a device on the network is the human-readable label of the system. It can be used to identify or connect to a system on the network instead of connecting to it via an IP address.

Displaying the Current Hostname

Regardless of your distribution, you can find out the current hostname of your system by running the hostname command:

Temporarily Changing the Hostname

The hostname command can also be used to change the hostname temporarily. In the terminal run:

…where NEWHOSTNAME is the new hostname you wish to use. Alphanumeric characters, dashes, and underscores only!

Changing the hostname via this method will only last to the next time your computer shuts down or reboots – it is a temporary change.

Permanently Changing the Hostname on Modern Releases of Ubuntu, Debian, RedHat/Centos, and Arch Based Linux Distributions

All commands from here on should be run as root or using sudo – administrative privileges are required.

Modern releases of Ubuntu, Debian, Arch, and other distributions based on them, utilize the SystemD set of system components – components that underpin the operating system and provide many of the system functions.

To permanently change the hostname on SystemD based systems, you can run the hostnamectl command in the terminal:

…where NEWHOSTNAME is the new hostname you wish to use. If you’re permanently changing your hostname, it’s probably worth rebooting after the change is made so that all services are aware of the change.

If you are running a Linux operating system released in the last few years, it’s most likely that it’s SystemD based, so this is probably what you’re looking for!

Permanently Changing the Hostname on Legacy Debian/Ubuntu Based Linux Distributions

Older versions of the above are not based on SystemD and lack the hostnamectl command, so you’ll have to edit some configuration files to change the hostname.

First, edit the /etc/hostname file (here I’m using the nano text editor):

The /etc/hostname file contains one thing and one thing only – a single line of text containing the system’s hostname.

Please note the current hostname for later, then edit it to what you want, save, and close.

Next, you’ll have to edit /etc/hosts:

There will be a line somewhere in the file that looks like this:

…where PREVIOUSHOSTNAME is the old hostname, which you made a note of in the last step. Change it so that it reads:

…where NEWHOSTNAME is the name you gave your system in the /etc/hosts file.

To apply the change, run:

Though as before, I recommend rebooting after changing the hostname so that all services are aware of the change – some may have cached it.

Permanently Changing the Hostname on RedHat/Centos Based Linux Distributions

Finally, here’s how to change the hostname on older versions of RedHat/Centos. Edit the following file:

The contents will look something like this (yours will probably differ slightly):

Find the line beginning with HOSTNAME= and replace the value following it (keeping the quotes) with the new hostname you wish to use.