How to Change Hostname on Ubuntu 20.04

A hostname is a unique identifier of a system on a network, used for management and communication between machines.

Ubuntu 20.04 supports both temporary and permanent hostname changes via CLI or GUI.

Check Current Hostname

hostname

hostnamectl

hostnamectl provides detailed system info including static, transient, and pretty hostnames.

Temporary Change (until reboot)

sudo hostname new-hostname

• applies instantly
• resets after reboot

Permanent Change (no reboot)

sudo hostnamectl set-hostname new-hostname

• applied immediately
• no reboot required

Permanent Change (with config files)

Edit:

sudo nano /etc/hostname

sudo nano /etc/hosts

Replace old hostname → new hostname.

Apply:

sudo systemctl reboot

Required for full system-level consistency.

Cloud Systems (Cloud-init)

Ensure persistence:

sudo nano /etc/cloud/cloud.cfg

Set:

preserve_hostname: true

Prevents hostname reset after reboot.

GUI Method

• Settings → About
• Change Device Name

Restrictions

• 1–63 characters
• alphanumeric + hyphens
• cannot start/end with hyphen

Summary

• temporary → hostname
• permanent → hostnamectl
• config files → /etc/hostname, /etc/hosts
• cloud → update cloud.cfg

Full guide 👉https://vsys.host/how-to/change-hostname-on-ubuntu-20-04