Show Disk Usage By Directories

We can use ncdu to see disk usage interactively in command-line only.

ncdu (NCurses Disk Usage) is a curses-based version of the well-known 'du', and provides a fast way to see what directories are using your disk space.

Usage

$ ncdu {OPTIONS} {DIRECTORY}

Example

$ ncdu -x /

Will show usage of / (root) directory.

Source: AskUbuntu