How does the chroot helper of the TUXEDO OS Live-ISO work? - TUXEDO Computers

The TUXEDO OS Live-ISO has a repair function to access the TUXEDO OS installation on your notebook from the Live-ISO. We explain how it works and what you can do with it.

What is a chroot?

The portmanteau word chroot stands for change root. This means you can use it to change to a different root directory. Among other things, a chroot can be used to access the file system of an installed system from a live ISO in order to repair it.

Our chroot implementation, which you can access via the main menu in the section TUXEDO of the TUXEDO Live-ISO, works with all popular distributions that follow the Filesystem Hierarchy Standard. This means you can repair installations of Ubuntu, Fedora, Linux Mint, OpenSUSE and other popular distributions with our chroot helper.

Chroot is not an invention of TUXEDO, but was first implemented in Unix in the 1970s and is present in Linux since the 90s. We have merely automated the process for you, which otherwise requires you to enter several commands in a terminal, that even weathered users have a hard time remembering.

What does a chroot do?

A chroot is often used as a versatile tool in software development. In our context, chroot can serve to repair an installed system. Imagine you have forgotten your password to log in to the installed TUXEDO OS or any other distribution described above. Another example would be a faulty entry in the /etc/fstab file. In that case, systemd will not allow the system to boot properly, it only boots read only and you cannot make any changes. In these and similar situations, a chroot can be helpful to resolve such issues.

How to create a chroot with TUXEDO OS Live ISO

If you haven’t already done so, download the latest TUXEDO OS image from our website and put it on a USB stick. To achieve this, we recommend the small tool USBImager, which you can download as a zip file, unzip and install as DEB. Detailed instructions on how to create a bootable live medium on a USB stick can be found in a separate article.

You can access the live system by booting your device with the USB stick inserted and pressing the F7 or on some devices the DEL key several times during early boot. You will enter the boot manager and determine your USB stick as boot device.

Once the live environment has booted up, open the main menu on the bottom left and open the submenu TUXEDO. There, you click on TUXEDO chroot helper to start the process. After clicking on the item, the system will check for an update of the chroot helper and install it, if available. After that, you will be presented with the following warning message:

As soon as you confirm the dialog, chroot helper mounts some directories that are necessary for full access to your installed system and completes the process after a few seconds with a root prompt to your installed system. From here you now have full access to your system and can solve existing issues.

You can test this, for example, by typing cd /home/USERNAME. After the obligatory enter, type ls -l, and you should see the structure of your home directory.

How do I change the root password in a chroot?

If you have forgotten your root password, enter the passwd command at the root prompt you just created. Then the system knows that you want to change your root password. You will be prompted to enter a new password and repeat it. Thereafter, the system confirms the change, and you have a new root password. When it comes to the user password, the passwd USERNAME command is used.

If you would like to fix an error in a configuration file like fstab, open the file in a writable fashion with nano /etc/fstab and make your changes. You save these with CTRL+O and leave the editor with CTRL+X. You can now leave the chroot by typing exit and you are back in the live media.

A word about encryption

In this context, we would like to remind you that physical possession of an unencrypted notebook gives an unauthorized person access to the entire contents with little effort. In this context, a savvy thief might realize that the chroot function allows him to change the root password. Therefore, it is important to encrypt notebooks that allow third party access. The chroot function is designed to detect encryption and request the password for it before the chroot is created.