How to Find Out What's Eating Up Your Disk Space: A Closer Look at NCDU and Other Tools


Disk space is a finite resource that can quickly run out if not managed properly. This is especially true with the increasing size of files and applications. When your disk space is running low, it’s crucial to identify which files and directories are using the most space so you can make informed decisions about what to delete, move, or compress. In this blog post, we’ll explore some of the most effective tools and methods for analyzing disk usage, with a special focus on ncdu (NCurses Disk Usage), a simple yet powerful tool designed for this purpose.

1. Understanding Disk Usage with ncdu:

ncdu is a disk utility for Unix systems that uses a text-based user interface. Unlike traditional command-line tools, ncdu provides an interactive experience, allowing you to navigate through your directories and delete files directly from the interface. It’s a lightweight and efficient program that can quickly scan your file system to display a detailed list of directories and their corresponding sizes.

To use ncdu, you can install it via your package manager (e.g., apt-get install ncdu on Debian-based systems or yum install ncdu on Red Hat-based systems). Once installed, you can start analyzing your disk space with the command ncdu /path/to/directory. It will provide a navigable interface to explore your directories sorted by size.

2. The Traditional du Command:

Before ncdu, the go-to command for checking disk usage was du (Disk Usage). This command-line tool generates a report of the space used by each directory and its subdirectories. You can use it with various flags, such as du -h for human-readable output or du -sh * to get a summary of each file and directory in the current directory. While not as user-friendly as ncdu, du is powerful for scripting and batch usage.

3. Visual Tools for Disk Analysis:

For those who prefer a graphical interface, there are several tools available:

  • Baobab (Disk Usage Analyzer): This is the default disk usage analyzer tool on GNOME desktops. It provides a visual representation of your disk usage with charts and lists, allowing you to quickly identify large files and directories.
  • WinDirStat: For Windows users, WinDirStat offers a detailed visual tree map of your file system, making it easy to spot the space hogs.
  • DaisyDisk: Mac users can utilize DaisyDisk, which offers a stylish and intuitive interface to scan disks and clean up unwanted files.

4. File Manager Integrations:

Many file managers, such as Nautilus on GNOME, Thunar on XFCE, and Dolphin on KDE, have built-in disk usage analysis tools. These can be accessed through the right-click context menu, often under ‘Properties’, giving you a quick overview of disk usage for a selected directory.

5. Command-Line Combinations and Scripts:

Advanced users might combine various command-line tools to create custom scripts for disk usage analysis. For example, using find with du can help you locate and size up specific file types, or you could pipe du output to sort and head to list the top ten largest directories.


Running out of disk space can be frustrating, but with the right tools, it’s a manageable problem. ncdu stands out for its simplicity and efficiency, providing a user-friendly interface to navigate and manage disk space. Whether you prefer command-line utilities, graphical applications, or your file manager’s built-in features, there are numerous ways to keep an eye on your disk usage. Regularly checking your disk space with these tools can help you maintain a healthy and efficient system.