System Rescue

If your system won’t boot, the “Enable/disable rescue mode” option gives you access to the hard drive. 

The configured rescue environment relies on Rescatux. Once you turn it on and boot up, you’ll first need to locate the original drive by running:

lsblk

This should list disk devices, such as /dev/sda1, which will correspond to your disk’s capacity (e.g., 50 GB).

Next, simply mount that device to a directory like /mnt with:

sudo mount /dev/sda1 /mnt

Carry out any necessary modifications.

When you’re finished, turn off rescue mode.