Rescue System

When your system fails to boot, the "Enable/disable rescue mode" option lets you gain access to the hard disk.

The Rescue system makes use of Rescatux. Once you’ve enabled it, boot up the machine, and you’ll need to locate the original hard disk first by running this command:

lsblk

You should then see the hard disk devices—for example, /dev/sda1, which should match up with the size of your hard disk (say, 50GB).

After that, all you need to do is mount the device to a folder, like /mnt, using this command:

sudo mount /dev/sda1 /mnt

Make any necessary changes as you see fit.

Once you’re done, disable rescue mode.