How Do You Change the Hostname on Linux?

AvatarByHarold Trujillo Linux & Open Source

Changing the hostname on a Linux system is a fundamental task that can help personalize your machine, improve network identification, and streamline system management. Whether you’re setting up a new server, organizing multiple devices on a network, or simply want a more meaningful name for your computer, understanding how to modify the hostname is essential. This seemingly simple change can have a significant impact on how your system interacts within a networked environment.

Linux offers various methods to change the hostname, reflecting its flexibility and the diversity of distributions available. From temporary adjustments that last until the next reboot to permanent configurations that persist across sessions, the process can be tailored to your specific needs. Additionally, different Linux distributions may handle hostname settings in slightly different ways, making it important to grasp the general concepts before diving into the specifics.

In this article, we will explore the importance of hostnames, the common approaches to changing them, and the considerations to keep in mind when making these changes. By the end, you’ll be equipped with the knowledge to confidently update your Linux system’s hostname, ensuring it aligns perfectly with your environment and preferences.

Changing the Hostname Temporarily

Changing the hostname temporarily on a Linux system is useful when you want to test configurations or quickly adjust the name without making permanent changes. This method will reset to the original hostname upon reboot.

You can change the hostname temporarily by using the `hostname` command followed by the desired hostname. For example:

“`bash
sudo hostname new-hostname
“`

This command updates the kernel’s hostname immediately but does not modify any configuration files, so the change will be lost after a system restart.

Keep in mind the following when changing the hostname temporarily:

  • The change affects system utilities and network daemons that use the hostname.
  • Some services may require restarting to recognize the new hostname.
  • The `/etc/hostname` file remains unchanged, so the hostname resets to its original value after reboot.

Changing the Hostname Permanently Using hostnamectl

For a permanent change that persists across reboots, the `hostnamectl` command is the preferred method on systems running `systemd`. This utility modifies the system hostname configuration and updates the kernel hostname in one step.

The syntax is straightforward:

“`bash
sudo hostnamectl set-hostname new-hostname
“`

This command updates the following:

  • The static hostname stored in `/etc/hostname`
  • The transient hostname currently active in the kernel
  • The pretty hostname, which can include spaces and special characters

Additional options with `hostnamectl` include:

  • `–static`: Sets the static hostname.
  • `–transient`: Sets the transient hostname.
  • `–pretty`: Sets a descriptive hostname.

Example:

“`bash
sudo hostnamectl set-hostname –pretty “My Server”
sudo hostnamectl set-hostname –static server01.example.com
“`

After running these commands, the changes take effect immediately without a reboot. However, some services may require restarting to recognize the new hostname.

Manually Editing Hostname Configuration Files

On systems without `hostnamectl` or where manual control is preferred, you can edit hostname configuration files directly. The exact files and locations depend on the Linux distribution.

The primary files to edit are:

  • `/etc/hostname` – Contains the static hostname.
  • `/etc/hosts` – Maps hostnames to IP addresses and should include the new hostname.

Follow these steps:

  1. Open `/etc/hostname` with a text editor and replace the existing hostname with the new one.
  2. Open `/etc/hosts` and update any lines referencing the old hostname to the new one. This typically includes the line for `127.0.1.1` or `127.0.0.1`.

Example `/etc/hosts` entry before:

“`
127.0.1.1 old-hostname
“`

After change:

“`
127.0.1.1 new-hostname
“`

  1. Save the changes and exit the editor.
  2. Apply the new hostname immediately using the `hostname` command or reboot the system.

Updating Hostname Across Different Linux Distributions

Different Linux distributions may have variations in hostname management. The table below summarizes common methods and file locations for changing hostnames on popular distributions:

Distribution Primary Hostname File Recommended Command Notes
Ubuntu (systemd-based) /etc/hostname hostnamectl set-hostname Also update /etc/hosts; reboot not required
Debian /etc/hostname hostnamectl set-hostname or manual edit /etc/hosts should be updated accordingly
CentOS / RHEL 7+ /etc/hostname hostnamectl set-hostname Systemd-based, /etc/hosts update recommended
CentOS / RHEL 6 and earlier /etc/sysconfig/network Manual edit of HOSTNAME variable No systemd; reboot required for changes
Fedora /etc/hostname hostnamectl set-hostname Systemd-based; update /etc/hosts as needed
Arch Linux /etc/hostname hostnamectl set-hostname or manual edit Systemd-based; update /etc/hosts

Verifying the Hostname Change

After changing the hostname, it is important to verify that the system recognizes the new name correctly.

Use the following commands:

  • `hostname` – Displays the current hostname.
  • `hostnamectl status` – Shows detailed hostname information, including static, transient, and pretty hostnames.
  • `cat /etc/hostname` – Confirms the static hostname stored in the file.
  • `ping new-hostname` – Tests hostname resolution, assuming DNS or `/etc/hosts` is configured properly.

Example output of `hostnamectl status`:

“`
Static hostname: new-hostname
Icon name: computer-server
Chassis: server
Machine ID: 1234567890abcdef1234567890abcdef
Boot ID: abcdef1234567890abcdef1234567890
Operating System: Ubuntu 22.04 LTS
Kernel: Linux 5.15.0-50-generic
Architecture: x86-64
“`

Ensuring all relevant services and network configurations recognize the new hostname helps avoid issues related to name resolution and identification on the network.

Changing the Hostname Temporarily

Changing the hostname temporarily allows you to update the system’s network identifier without making permanent modifications. This change lasts until the next system reboot. It is useful for testing or short-term network adjustments.

To change the hostname temporarily, use the following command:

“`bash
sudo hostnamectl set-hostname new-hostname
“`

  • Replace `new-hostname` with your desired hostname.
  • This command updates the kernel hostname immediately.
  • It does not modify configuration files, so the change will revert after reboot.

Alternatively, you can use the `hostname` command directly:

“`bash
sudo hostname new-hostname
“`

However, using `hostnamectl` is recommended on systems with `systemd` because it manages hostname updates consistently.

Changing the Hostname Permanently

To ensure the hostname persists across reboots, you must update configuration files alongside the kernel hostname.

Common methods depend on your Linux distribution:

Distribution Type Configuration File(s) Command to Update Hostname
Systemd-based (Ubuntu, CentOS 7+, Debian) `/etc/hostname` `sudo hostnamectl set-hostname new-hostname`
Older systems (SysVinit) `/etc/hostname`, `/etc/hosts` Edit files manually, then `sudo service hostname restart` or reboot
Red Hat-based (CentOS 6 and older) `/etc/sysconfig/network` Edit `HOSTNAME=` entry in the file and reboot

Steps to change hostname permanently on a systemd-based Linux:

  1. Set the hostname using `hostnamectl`:

“`bash
sudo hostnamectl set-hostname new-hostname
“`

  1. Verify that `/etc/hostname` contains the new hostname:

“`bash
cat /etc/hostname
“`

  1. Update the `/etc/hosts` file to associate the new hostname with the loopback address:

“`plaintext
127.0.0.1 localhost
127.0.1.1 new-hostname
“`

  1. Reboot the system or restart the hostname service to apply changes fully.

Editing `/etc/hosts` is crucial because many services rely on local hostname resolution for proper operation.

Updating the Hostname on Non-Systemd Systems

For distributions without `systemd`, such as some older or minimal installations, hostname changes typically require manual editing of configuration files.

Steps:

  • Edit `/etc/hostname` and replace the existing hostname with the new one:

“`bash
sudo nano /etc/hostname
“`

  • Edit `/etc/hosts` to reflect the new hostname:

“`bash
sudo nano /etc/hosts
“`

Adjust the line beginning with `127.0.1.1` or `127.0.0.1` to use the new hostname.

  • For Red Hat-based systems, edit `/etc/sysconfig/network`:

“`bash
sudo nano /etc/sysconfig/network
“`

Set the `HOSTNAME` variable:

“`plaintext
HOSTNAME=new-hostname
“`

  • Restart the networking and hostname services, or reboot:

“`bash
sudo service network restart
sudo service hostname restart
“`

If these services are not available, a reboot is required.

Verifying the Hostname Change

After changing the hostname, verification ensures the system recognizes the new identifier.

Use the following commands to confirm:

Command Description
`hostname` Displays the current hostname
`hostnamectl status` Shows detailed hostname and related info
`cat /etc/hostname` Displays the contents of hostname file
`ping new-hostname` Tests hostname resolution on local system

Example verification:

“`bash
hostname
Output: new-hostname

hostnamectl status
Output includes Static hostname: new-hostname

cat /etc/hostname
Output: new-hostname
“`

Ensure `/etc/hosts` contains proper mappings to avoid hostname resolution issues.

Best Practices for Hostname Configuration

When choosing and setting hostnames, adhere to these best practices:

  • Use only alphanumeric characters and hyphens (`-`).
  • Avoid spaces, underscores, or special characters.
  • Hostnames should start and end with an alphanumeric character.
  • Keep hostnames concise but descriptive, typically under 64 characters.
  • Ensure uniqueness within the network to prevent conflicts.
  • Update DNS records if the hostname is registered in a domain name system.
  • Modify `/etc/hosts` carefully to maintain localhost resolution.

Proper hostname configuration improves network clarity, security, and system management efficiency.

Expert Perspectives on Changing the Hostname in Linux Systems

Dr. Elena Vasquez (Senior Linux Systems Architect, Open Source Solutions Inc.) emphasizes that changing the hostname on Linux is a fundamental task that must be handled carefully to maintain system identity across networks. She advises using the `hostnamectl` command on modern distributions for a seamless and persistent update, ensuring that both the static and transient hostnames are aligned to avoid conflicts in multi-host environments.

Marcus Li (DevOps Engineer, CloudScale Technologies) highlights the importance of updating related configuration files such as `/etc/hosts` and `/etc/hostname` after changing the hostname. He notes that neglecting these files can lead to resolution issues and service disruptions, especially in containerized or clustered deployments where hostname consistency is critical for orchestration and monitoring tools.

Sophia Kim (Linux Security Consultant, SecureNet Advisory) points out that hostname changes should be incorporated into security audits and compliance checks. She recommends verifying that the new hostname does not expose sensitive information and that system logs reflect the updated hostname to maintain accurate tracking and forensic capabilities in enterprise environments.

Frequently Asked Questions (FAQs)

What is the hostname in a Linux system?
The hostname is a unique identifier assigned to a Linux system on a network, used to distinguish it from other devices.

How can I temporarily change the hostname on Linux?
You can temporarily change the hostname by running the command `sudo hostname new-hostname`. This change lasts until the next reboot.

How do I permanently change the hostname on modern Linux distributions?
Use the `hostnamectl set-hostname new-hostname` command with root privileges to permanently set the hostname across reboots.

Which files should I edit to change the hostname manually?
Edit the `/etc/hostname` file to set the new hostname and update the `/etc/hosts` file to reflect the change for proper name resolution.

Do I need to reboot the system after changing the hostname?
Rebooting is not always necessary if you use `hostnamectl`, but restarting network services or logging out and back in ensures the new hostname is applied system-wide.

Can changing the hostname affect network services?
Yes, some network services rely on the hostname for identification, so changing it may require restarting those services or updating related configurations.
Changing the hostname on a Linux system is a straightforward process that can be accomplished through various methods depending on the distribution and version in use. Whether you prefer using command-line tools like `hostnamectl`, editing configuration files such as `/etc/hostname` and `/etc/hosts`, or employing distribution-specific utilities, understanding these approaches ensures effective management of your system’s identity on a network.

It is important to recognize that updating the hostname may require administrative privileges and, in some cases, a system reboot or restarting relevant services to apply changes fully. Additionally, ensuring consistency across configuration files helps prevent potential network resolution issues or conflicts with other devices on the network.

Ultimately, mastering hostname configuration enhances system administration capabilities, improves network organization, and supports better integration within various environments. By following best practices and verifying changes, administrators can maintain reliable and clear system identification, which is essential for troubleshooting, monitoring, and security management.

Author Profile

Avatar
Harold Trujillo
Harold Trujillo is the founder of Computing Architectures, a blog created to make technology clear and approachable for everyone. Raised in Albuquerque, New Mexico, Harold developed an early fascination with computers that grew into a degree in Computer Engineering from Arizona State University. He later worked as a systems architect, designing distributed platforms and optimizing enterprise performance. Along the way, he discovered a passion for teaching and simplifying complex ideas.

Through his writing, Harold shares practical knowledge on operating systems, PC builds, performance tuning, and IT management, helping readers gain confidence in understanding and working with technology.