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How To Fix Login Issues in Ubuntu 20.04 on Raspberry Pi 4

Ubuntu 19

Ubuntu 20.04 is a popular choice for running on Raspberry Pi 4 due to its stability and wide range of supported software. However, you may encounter login issues after installing the operating system. This article will guide you through several methods to fix these issues.

Quick Answer

To fix login issues in Ubuntu 20.04 on Raspberry Pi 4, you can try waiting for the initial cloud-init and SSH-key creation processes to complete before logging in with the default credentials. If that doesn’t work, you can reset the password using the chroot command or edit the password file directly. If none of these solutions work, it’s important to ensure you have the correct Ubuntu version for your Raspberry Pi model and that the installation is not corrupted. Seek assistance from the Ubuntu community or consult the official documentation for further troubleshooting steps.

Initial Waiting Period

After the first boot of your Raspberry Pi with Ubuntu 20.04, it may take a few minutes for the cloud-init and SSH-key creation processes to complete. During this time, the default credentials (ubuntu/ubuntu) may not work.

Wait until you see the cloud-init and SSH-key creation messages on the screen, and then try logging in with the default credentials again.

Reset the Password Using Chroot

If the default credentials still do not work, you can try resetting the password using the chroot command. This command allows you to operate on a Linux system from another one, such as the one on your SD card. Here are the steps:

  1. Mount the SD card in read-write mode on a Linux system using the mount command. The command might look like this: mount /dev/sdc1 /mnt. Here, /dev/sdc1 is the SD card and /mnt is the mount point.
  2. Use the chroot command to enter the mounted SD card. The command is simply chroot /mnt. This command changes the root directory to /mnt (the SD card) and runs the shell, allowing you to operate on the SD card as if it were the main system.
  3. Use the passwd command to change the user password. The command is passwd ubuntu, where ubuntu is the username. You will be prompted to enter the new password twice.
  4. Reboot the Raspberry Pi and try logging in with the new password.

Edit the Password File

If resetting the password does not work, you can edit the password file directly to set a blank password for the user. Here’s how:

  1. Mount the SD card in read-write mode on a Linux system.
  2. Locate the password file, usually located at /mnt/etc/shadow. This file contains the hashed passwords for all users.
  3. Find the line containing the username and hashed password, and remove the hashed password. The line might look like this: ubuntu:$6$.... Remove everything between the first and second colons.
  4. Save the changes and unmount the SD card using the umount command.
  5. Reboot the Raspberry Pi and try logging in with a blank password for the user.

Remember not to modify the root user as it cannot directly log in to the Ubuntu OS.

Conclusion

If none of these solutions work, make sure you have installed the correct Ubuntu version for your Raspberry Pi model and followed the installation tutorial correctly. It’s also essential to ensure that the installation is not corrupted.

If you continue to experience issues, it may be helpful to seek assistance from the Ubuntu community or consult the official documentation for further troubleshooting steps.

By following these steps, you should be able to resolve most login issues with Ubuntu 20.04 on Raspberry Pi 4.

What is the default username and password for Ubuntu 20.04 on Raspberry Pi 4?

The default username and password for Ubuntu 20.04 on Raspberry Pi 4 are "ubuntu" for both the username and password.

How long should I wait for the cloud-init and SSH-key creation processes to complete?

It may take a few minutes for the cloud-init and SSH-key creation processes to complete. It is recommended to wait until you see the cloud-init and SSH-key creation messages on the screen before attempting to log in with the default credentials.

What should I do if the default credentials still do not work?

If the default credentials still do not work, you can try resetting the password using the chroot command or editing the password file directly. Please refer to the steps mentioned in the article for detailed instructions.

Can I set a blank password for the user?

Yes, you can set a blank password for the user by editing the password file directly. Please follow the steps mentioned in the article to remove the hashed password from the password file. However, it is generally recommended to set a strong password for better security.

What should I do if none of the solutions work?

If none of the solutions mentioned in the article work, ensure that you have installed the correct Ubuntu version for your Raspberry Pi model and followed the installation tutorial correctly. It is also important to check for any potential installation corruption. If the issues persist, seeking assistance from the Ubuntu community or consulting the official documentation for further troubleshooting steps is recommended.

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