gdu — Pretty Fast Disk Usage Analyzer Written in Go

Introduction

gdu is the Go counterpart to dua-cli and ncdu: point it at a mount, it scans with a pool of goroutines, and gives you an interactive TUI to drill into the tree. Its differentiator is fast SSD-tuned scanning, a CI-friendly non-interactive mode, and a tiny static binary you can ship into Alpine-based images.

What gdu Does

• Parallel filesystem scan using goroutines.
• Interactive TUI for navigation and deletion.
• Non-interactive mode emits a top-N summary or JSON.
• Size modes: apparent, real (with blocks), inode count.
• Mount-point aware; can stay on or cross filesystems.

Architecture Overview

gdu uses a worker pool driven by a channel of directory tasks; file stats are aggregated into a tree protected by per-node atomic counters. The TUI uses tview. Non-interactive mode short-circuits the renderer and writes results to stdout or a file.

Self-Hosting & Configuration

• Install via brew, apt (snap), dnf, scoop, or GitHub release.
• gdu -h shows flags; config is env-driven (GDU_OUTPUT_FILE, etc.).
• Ignore globs via -I.
• Max cores via GOMAXPROCS.
• Alpine-compatible static binary ≈ 4MB.

Key Features

• Fast on SSDs — dozens of goroutines saturate NVMe.
• Works equally well interactive or headless.
• JSON output for dashboards and trending.
• Mount-point awareness for containers.
• Delete and mark features inside TUI.

Comparison with Similar Tools

• ncdu — classic single-threaded TUI.
• dua-cli — Rust equivalent; similar UX.
• dust — read-only bar chart.
• baobab (GNOME) — GUI; not useful on servers.
• df + du combo — scriptable but slow.

FAQ

Q: Does gdu need root? A: Only to see files unreadable by your user.

Q: JSON schema stable? A: Yes; used by Grafana dashboards.

Q: Can I exclude bind mounts? A: --no-cross stays on the current filesystem.

Q: Works on Windows? A: Yes — stats reported via os.FileInfo.

Sources

• https://github.com/dundee/gdu