Find what is using disk space on Ubuntu—before deleting anything

Applies to: Ubuntu 24.04 LTS with GNU Coreutils · Time: About 10–15 minutes, plus scan time · Difficulty: Beginner

A “disk full” warning is a reason to investigate, not a reason to start removing unfamiliar folders. First identify which filesystem is running short of room. Then narrow the search to a folder you recognize. This guide uses read-only reports to answer both questions before you choose any cleanup action.

The distinction matters: df describes a filesystem’s capacity; du estimates space attributed to files under a chosen path. A small Downloads folder does not prove that the filesystem holding Ubuntu has plenty of room.

Before you start

Save your work and open Terminal. You need permission to read the folders you inspect. No administrator commands, deletion commands, package changes, or disk repairs are part of this walkthrough. Close busy applications if you want a more stable comparison, because changing files can change the reports while a scan is running.

The commands target GNU tools documented for Ubuntu 24.04 LTS. They are not instructions for Windows PowerShell or macOS utilities. If you use another release or a customized system, check the implementation first: each command below should identify GNU Coreutils. Stop and consult your system’s documentation if it does not.

df --version
du --version
sort --version

1. Check the filesystem holding your Home folder

df -h -- "$HOME"

$HOME expands to your account’s Home directory; keep the double quotes. The -- separates options from the path. You do not replace either with your username. Read the Avail and Use% columns, and note Mounted on, which identifies the reported mount point. The -h option uses readable units based on powers of 1024.

This reports the filesystem containing Home, not just the size of your personal files. Home may share the root filesystem, or it may have its own filesystem. To check the filesystem at the system root separately, run:

df -h -- /

Compare the mount points. If both commands report the same one, they are describing the same pool of space. If the full filesystem is elsewhere, such as an external drive, use an existing folder on that drive as the argument instead. Do not decide which files to move until you know which filesystem actually needs room.

2. Find the larger folders inside Home

du -xh --max-depth=1 -- "$HOME" | sort -h

This walks your Home directory and prints a total for Home and for each immediate subdirectory. --max-depth=1 limits the displayed levels; it does not avoid scanning deeper contents to calculate those totals. -x skips directories on different filesystems. -h formats the estimates, and sort -h orders those human-readable sizes from small to large. Look near the bottom for larger entries.

The entry for Home is the parent total. Do not add that total to its children: that would count their space again. Hidden directories are included because the command scans Home itself rather than relying on a shell wildcard. A large hidden directory is a clue to investigate, not permission to erase it.

Wait until the normal prompt returns. A long pause can simply mean there are many entries to inspect. You can press Ctrl+C to cancel; an interrupted listing is incomplete. Do not hide permission errors: an unreadable subtree can make a reported total incomplete, even when the sorted output looks tidy.

3. Follow one useful lead

Suppose the report points to Downloads. Scan that directory next:

du -xh --max-depth=1 -- "$HOME/Downloads" | sort -h

Downloads is an example. If your system uses a localized folder name, or the large folder is somewhere else, replace the quoted path with its actual path. Keep the quotes around paths containing spaces. Repeat one level at a time instead of requesting a huge listing of every file on the computer.

Open the selected folder in Files and review what it contains. The command above shows directory totals; it does not print every individual file. A parent can be large because it holds large files directly, even if its listed subdirectories are small. Use the file manager’s size column to inspect those files. Names beginning with a dot can contain application settings or personal data; their names do not establish that they are disposable.

Prefer a visual scan? Use Disk Usage Analyzer

If Disk Usage Analyzer is installed, open it from your applications. GNOME’s documentation describes selecting your Home folder from Devices & Locations. For a narrower investigation, use Scan Folder… from its window menu and select the folder you want to inspect.

A chart can make one unusually large folder easier to notice. Start with your own folders and allow the scan to finish. The analyzer’s folder view is still an investigation aid: it does not decide which files you need. This guide does not require installing another application just to obtain the command-line reports.

4. If space looks available, check inodes too

df -i -- "$HOME"

Some filesystems can run short of inodes—records used to track files and other filesystem objects—even when byte capacity remains. Read IFree and IUse%. A very high inode-use percentage points to a different investigation from one oversized video. The numbers and limits depend on the filesystem; do not treat this as a universal repair recipe.

If an application still reports a full disk, recheck the filesystem where it is actually trying to write. A Home-directory scan cannot account for everything elsewhere on the system. Record the exact application error along with the relevant mount point before seeking help.

Why the totals may not agree

Do not expect a Home-directory du total to equal the Used column from df. One describes a selected tree; the other describes an entire filesystem. Other users’ files, system directories, skipped mounts, and unreadable folders are outside this scan’s scope. Filesystem features such as compression and shared blocks can also make allocation estimates less straightforward.

The reports do not certify disk health or prove that a backup works. If a drive disconnects or produces I/O errors, stop treating this as a normal tidying exercise. Preserve the error and get help with the device or filesystem rather than repeatedly trying cleanup commands.

Finish with a decision, not an automatic deletion

A useful result is specific: you know the constrained mount point and have identified a folder whose contents you understand. If you later choose to move personal files, confirm the destination and verify the copy before removing the original. Deleting files, emptying Trash, and uninstalling applications are separate decisions with different consequences.

These commands make no intended changes to your file contents or installed packages, so there is no cleanup action to roll back. If you separately free space, rerun the same df command against the same path to check the result rather than comparing unrelated mount points.

If you reached this page because a package installation failed, our beginner’s APT installation guide explains the normal workflow and why you should read proposed package changes. Disk-space investigation comes before trying another installation.

Sources

Ubuntu 24.04’s manuals for df and du; GNU’s df, du, and sort documentation; and GNOME’s instructions for scanning Home and scanning a folder.

The command forms were checked on a small synthetic directory tree using GNU Coreutils 9.10 on Debian, including a hidden directory, a path containing spaces, and human-readable sorting. This was not an Ubuntu 24.04 desktop test, a full-disk scan, a permissions-error test, or a hardware-health test.

Optional gear

Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases, at no extra cost to you. Commissions do not influence our recommendations.

Samsung T7 Shield 1TB portable SSD on Amazon (paid link). An optional destination for additional file copies. Copy and verify files before considering deletion; buying a drive does not automatically free space. Keep another independent copy.

AI-generated category illustration; not a product photo.

You do not need to buy anything to follow this article. Check the exact model, seller and compatibility before buying.