ncdu

Overview

ncdu (NCurses Disk Usage) is an interactive du for finding what consumes space. Faster feedback than reading raw du trees; great on full root filesystems.

sudo apt install ncdu

Syntax

ncdu [options] [path]

Common Options

Option	Description
-x	One filesystem only
-r	Read-only (no delete)
-o file	Export scan
-f file	Load export
-e	Extended info (more stat calls)
--exclude pattern	Skip paths

Examples with Explanations

Scan root (one FS)

sudo ncdu -x /

Navigate with arrows; d deletes (if not -r); q quits.

Home directory

ncdu -x "$HOME"

Export for later / remote analysis

sudo ncdu -x -o /tmp/root.ncdu /
ncdu -f /tmp/root.ncdu

Notes & Pitfalls

• Needs read permission; use sudo for system trees.
  
• Exclude bind mounts and huge network mounts with -x / --exclude.
  
• Deleting from ncdu is still delete — careful on production.

Related Commands

• du / dust / duf — other usage views
  
• df — filesystem free space
  
• find — age-based cleanup

Additional Resources

• man ncdu