Ubuntu Initial Password Setup and Reset Guide | A Complete Guide for Beginners

By 佐川 直弘 | Naohiro Sagawa (運営者)

※記事内に広告を含みます。Amazonアソシエイトとして適格販売により収入を得ています。　

1. Introduction

Ubuntu is one of the most widely used Linux distributions, loved by both beginners and advanced users. Its simple and user-friendly interface, along with a rich support community, makes it an excellent choice for those using Linux for the first time.

However, many users face questions or issues related to the “initial password” when installing Ubuntu for the first time. Common concerns include, “What is the root account password?” or “What should I do if I set the password incorrectly?”

This article provides a clear explanation of Ubuntu’s initial password system, setup methods, and solutions in case you forget your password. Additionally, we cover security measures and offer useful information for users utilizing WSL (Windows Subsystem for Linux), not just beginners.

Benefits of Reading This Article

• Understand the basic structure of the initial password and root account.
• Learn how to reset your password if you forget it.
• Discover ways to enhance Ubuntu’s security.

If you’re struggling with initial settings after installing Ubuntu or feel unsure about handling the root account, this guide will help you navigate these challenges smoothly. We hope this article enhances your Ubuntu experience.

2. What is the Initial Password in Ubuntu?

Many users have questions about the “initial password” when installing Ubuntu for the first time. This section explains the fundamental concept behind Ubuntu’s initial password and its background.

When is the Initial Password Set?

During the Ubuntu installation process, you create the first user account, which is typically granted administrator privileges. The password set at this stage becomes the “initial password” used after installation.

Importantly, this password is linked to the created regular user account, not the root account. By default, Ubuntu disables the root account, making direct login as root unavailable.

What is the Root Account?

In Linux systems, the “root account” holds the highest administrative privileges, allowing full control over system settings and configurations. However, for security reasons, Ubuntu disables direct login to the root account.

Instead, Ubuntu employs the sudo command, allowing regular administrator users to temporarily acquire root privileges. This approach helps prevent unintended system modifications and security risks.

The Root Account’s Initial Password

By default, the root account in Ubuntu does not have a password. In its initial state, the root account’s password is empty, and users cannot log in unless they explicitly enable it.

Why is the Initial Password Important?

The initial password acts as the first line of defense for system access. The password set during installation is used in the following situations:

• First-time login
• Authentication when executing sudo commands
• Verifying changes in applications and settings

Therefore, it is crucial to choose a strong and secure initial password.

Risks of Forgetting Your Password

If you forget your initial password, you may lose access to your system. Refer to the “Password Reset Methods” section later in this article to troubleshoot and recover access.

3. How to Set the Root Password

By default, Ubuntu disables the root account, preventing direct login. However, in certain cases, you may need to enable the root account and set a password. This section provides a step-by-step guide to configuring the root password.

When Should You Enable the Root Account?

In most cases, using the sudo command for administrative tasks is recommended. However, enabling the root account may be useful in the following situations:

• When direct access to the root shell is necessary for system recovery.
• When performing advanced configurations or frequently running scripts requiring root privileges.

However, enabling the root account increases security risks and the possibility of accidental system modifications, so proceed with caution.

Steps to Set the Root Password

Follow these steps to configure the root password in Ubuntu.

1. Open the Terminal

• Log in as a user with administrator privileges and open the terminal.

1. Gain Root Privileges Using sudo
   Enter the following command and provide your current user password:

   sudo -i

This command switches you to the root shell.

3. Set the Root Password Using the passwd Command
   Run the following command to set a new root password:

   passwd root

When prompted, enter and confirm the new password.

4. Verify Successful Setup
   If the password change is successful, you will see a confirmation message:

   password updated successfully

5. Ensure the Root Account is Enabled
   Although already enabled, check that the account is not locked by running:

   passwd -S root

If the result shows active, the root account is enabled.

Verifying the Configuration

If you need to log in as the root account, you can switch to it using:

su -

After finishing your work, always log out to avoid security risks.

Security Considerations

• Use a Strong Password
  Set a password that is at least 8 characters long and includes a mix of letters, numbers, and special characters.
• Minimize Root Account Usage
  Continue using sudo for everyday administrative tasks.
• Monitor Login Activity
  Regularly check the auth.log file for suspicious login attempts:

  cat /var/log/auth.log | grep "root"

4. What to Do If You Forget Your Password

While using Ubuntu, you may forget your administrator or root account password. This section provides detailed steps to reset your password and regain access to your system.

Steps to Reset Your Password

Ubuntu allows you to reset your password using the GRUB (Grand Unified Bootloader) recovery mode.

Resetting Your Password Using GRUB

1. Restart Your System

• During startup, press the Shift key (or Esc key for UEFI) to display the GRUB menu.

1. Select Recovery Mode

• From the GRUB menu, choose the kernel entry labeled “Recovery Mode,” which typically appears as:
  Ubuntu, with Linux <version number> (recovery mode)

1. Start the Root Shell

• From the recovery mode menu, select “root” to launch the root shell.
• You should see a prompt like this:
  root@hostname:~#

1. Remount the File System

• Since the recovery mode mounts the file system as read-only, make it writable by running:
  mount -o remount,rw /

1. Change the Password Using passwd

• Reset the password for the desired user account by running:
  passwd <username>
  Enter and confirm the new password when prompted.

1. Restart Your System

• Once the password change is successful, reboot your system using:
  reboot
• After restarting, you can log in with your new password.

Important Considerations for Password Reset

• Physical Access Requirement
  You need physical access to the machine to reset the password through recovery mode. Ensure only authorized users can access your system.
• Data Safety
  Resetting the password does not erase your data, but it is always advisable to back up your important files beforehand.
• Alternative Solutions
  If GRUB does not appear or fails to work, try using an Ubuntu installation media to boot into a recovery environment.

5. Managing Passwords in WSL (Windows Subsystem for Linux)

WSL (Windows Subsystem for Linux) allows you to run Linux environments on Windows. Even in WSL, proper password management is crucial. This section explains how to set and reset passwords in WSL.

Differences in Password Management in WSL

WSL operates similarly to standard Ubuntu installations but has key differences:

• WSL is integrated with Windows user accounts and does not have a traditional system boot process.
• The root account is enabled by default, and administrative tasks use the sudo command.

Setting or Changing Your Password in WSL

Follow these steps to manage your user password in WSL.

1. Open the Terminal

• Launch “Ubuntu” from the Windows Start menu to open the terminal.

1. Use the passwd Command

• To set or change your password, run:
  passwd
• Enter your current password (if set), followed by the new password twice.

1. Change Another User’s Password

• To reset the password for a specific user, use:
  sudo passwd <username>

Resetting Your Password in WSL

If you forget your password in WSL, you can reset it using the root account.

1. Start WSL as Root

• Open Windows PowerShell or Command Prompt and run:
  wsl -u root

1. Reset the Password Using passwd

• Reset a user’s password with:
  passwd <username>
• Enter and confirm the new password.

1. Exit Root Mode

• After resetting, return to your normal user session by running:
  exit

Security Best Practices

• Minimize Root Account Usage
  Since WSL enables the root account by default, avoid using it for daily operations.
• Protect Your Password
  Use a strong password and prevent unauthorized access.
• Manage WSL Instances
  If deleting a WSL instance, ensure all critical data is backed up beforehand.

6. Security Measures and Best Practices

To keep your Ubuntu system secure, follow these best practices for password and account management.

Creating a Strong Password

Follow these tips to create a strong password:

• Length: At least 12 characters.
• Complexity: Use a mix of uppercase, lowercase, numbers, and symbols.
• Unpredictability: Avoid dictionary words and personal information.
• Uniqueness: Use different passwords for different accounts.

Example:

s3cUr3!P@ssw0rd123

Regularly Update Your Password

passwd

Monitor Logins

sudo cat /var/log/auth.log | grep "root"

7. Conclusion

Proper password management is essential for maintaining security in Ubuntu. This article covered:

• The importance of the initial password and how it works.
• How to set and reset the root password.
• Security best practices for protecting your system.

Next Steps

1. Practice managing your Ubuntu passwords.
2. Explore advanced Ubuntu security settings.

By following these practices, you can enhance the security and usability of your Ubuntu system.