How to Install NCDU on a Synology NAS (DSM 7.1) – Quick Guide

If you’re running a Synology NAS and need an easy way to find out which folders and files are consuming disk space, NCDU (NCurses Disk Usage) is one of the best tools available.

This guide shows how to install NCDU on a Synology RS2416+ running DSM 7.1, but the same method should work on most Synology NAS models with an x86_64 CPU architecture.

Verify Your Synology Architecture

Connect to your Synology via SSH and run:

uname -a

Example output:

root@NAS01:/tmp# uname -a
Linux NAS01 3.10.108 #42962 SMP Tue Jul 29 14:28:52 CST 2025 x86_64 GNU/Linux synology_avoton_rs2416+

The important part is:

x86_64

This means you need the x86_64 version of NCDU.

Download the NCDU Binary

Visit the official NCDU website:

https://dev.yorhel.nl/ncdu

At the time of writing, the latest x86_64 Linux package is:

https://dev.yorhel.nl/download/ncdu-2.9.1-linux-x86_64.tar.gz

Install NCDU on Synology DSM

1. Connect via SSH

Enable SSH in DSM and connect to your NAS:

ssh admin@your-synology-ip

2. Download and Install NCDU

Run the following commands:

cd /tmp
wget https://dev.yorhel.nl/download/ncdu-2.9.1-linux-x86_64.tar.gz
tar -zxvf ncdu-2.9.1-linux-x86_64.tar.gz
cp /tmp/ncdu /usr/local/bin/
chmod +x /usr/local/bin/ncdu

Test the Installation

To verify that NCDU is working correctly, scan your main storage volume:

ncdu /volume1

NCDU will analyze the disk usage and present an interactive interface where you can quickly identify large folders and files.

Why Use NCDU on Synology?

NCDU offers several advantages over the built-in Synology storage tools:

• Fast disk usage analysis
• Interactive terminal interface
• Easily find large files and folders
• Works well over SSH
• Lightweight and efficient

For NAS administrators and home lab enthusiasts, NCDU is one of the most useful tools for troubleshooting storage issues and reclaiming disk space.

Conclusion

Installing NCDU on a Synology NAS is straightforward when using the official x86_64 binary. Once installed, it becomes an invaluable tool for tracking down storage usage and identifying folders that consume the most disk space.

If you’re running DSM 7.x on an x86_64-based Synology, NCDU is definitely worth adding to your toolbox.