See exactly where your disk space goes with QDirStat

A scan can slow down on directories with many small files, network mounts, permission errors or sleeping disks. Wait for active storage to respond, exclude unnecessary mount points and test a smaller directory to separate a performance issue from a permissions problem.

Missing folders usually indicate insufficient permissions, an unmounted path, an excluded filesystem or a scan started from a narrower directory. Check the selected root and read permissions before repeating the scan.

QDirStat totals visible files it can read, while filesystem tools can include reserved blocks, deleted-but-open files, metadata, snapshots and other allocation details. The figures answer different questions, so a difference does not automatically indicate an error.

Start with the smallest relevant directory, avoid slow network paths, close heavy disk workloads and use cache files for repeat analysis where appropriate. Scanning as a regular user also avoids traversing protected areas you may not need.

Cache files store a previously collected directory tree so QDirStat can reopen the analysis without reading every file again. They are useful for remote systems, scheduled scans or large trees that change slowly.

Root access provides broad visibility but also increases the consequences of a cleanup mistake. Prefer a normal account. Use elevated access only for a specific protected path, and avoid configuring destructive cleanup actions during a privileged session.

The mount may use permissions, access control lists, container restrictions or network credentials that block your account. Confirm the mount is active, then test read access from the shell before troubleshooting QDirStat itself.

Use QDirStat for identification first. Verify the full path, understand the owning application, back up irreplaceable data and remove files through the application when it manages its own database or cache. Never delete a large item only because it appears at the top.

It can analyze remote storage that is mounted as a readable filesystem, but performance may be limited by latency and file count. A cache generated close to the data can be more efficient than repeatedly scanning over a slow connection.

Extract the archive, read the project documentation, install the stated build dependencies and compile it in a user-owned working directory. The provided ZIP is source code, not a one-click Windows installer, so a development toolchain may be required.