ncdu (NCurses Disk Usage) Guide

ncdu is a disk usage analyzer with an ncurses interface. It is designed to find space hogs on a remote server where you don’t have an entire graphical setup, but it is useful even on regular desktop systems.

Basic Usage

To scan the current directory:

ncdu

To scan a specific directory:

ncdu /path/to/directory

To scan the entire filesystem (starting at root):

ncdu /

Useful Flags

-x: Stay on the same filesystem (don’t cross mount points).
-r: Read-only mode (prevents accidental deletion).
-o <filename>: Export the results to a file for later viewing.
-f <filename>: Import a previously exported result file.

Once ncdu is running, use these keys to navigate and interact:

Movement

Up/Down or j/k: Move the cursor.
Right or Enter: Open/descend into the selected directory.
Left or <: Go back to the parent directory.

Sorting

n: Sort by name (ascending/descending).
s: Sort by size (ascending/descending).
C: Sort by number of items.
M: Sort by last modified time (requires -e flag).

Display Options

g: Toggle between graph, percentage, or both.
a: Toggle between showing disk usage and apparent size.
e: Show/hide hidden files.
i: Show information about the selected item.

Actions

d: Delete the selected file or directory (asks for confirmation).
q: Quit ncdu.

Remote Usage

To scan a remote directory and view it locally:

ssh user@remote "ncdu -o- /path/to/dir" | ncdu -f-

This runs the scan on the remote server, pipes the output to your local machine, and displays it in your local ncdu instance.