This folder reports 460 GB. It is using 33.

Where 428 gigabytes go missing

Four mechanisms break the naive sum, and all four are ordinary. You do not have to do anything unusual to hit them. Most tools model none of them. Plumb models all four, on macOS, Linux and Windows.

Hardlinks

One file, several names. The filesystem stores its blocks once; every tool that sums the size of each name counts them once per name. Delete one name and you free nothing at all.

Copy-on-write clones

On APFS, copying a file writes no data. The copy reports its full length and shares every block with the original until one of them is edited. Time Machine’s local snapshots are built the same way.

Sparse files

A container disk image advertises the size it may one day reach and occupies only what it has written. This is where the 461 GB above comes from, and 428 GB of it does not exist.

Snapshots

Blocks a snapshot still references survive the file that referenced them. You can delete something, watch it disappear, and see no change in free space until the snapshot expires.

Three commands, and you can check it yourself

A 50 MiB file, a second name for the same file, and a separate 10 MiB file. The apparent size is 110 MiB. The disk is holding 60. This exact fixture runs on Windows, Linux and macOS in continuous integration on every commit, because it is the whole thesis in one assertion.

$ dd if=/dev/zero of=big.bin bs=1m count=50
$ ln big.bin hard.bin # a second name, not a second file
$ plumb scan .

  logical      110.00 MB
  allocated    60.01 MB
  freeable     60.01 MB  <- what deleting actually frees
  shared       1 entries share blocks with another path

# du -sk agrees: 61452 KiB.

Eight ways to look at the same tree

Every view can be sized by reclaimable bytes, allocated bytes, or logical bytes. Switching between them is the fastest way to see the gap this project exists to measure. All eight are rasterized in Rust and drawn as a single image, which is why a quarter of a million nodes stays interactive.

Treemap

Squarified, so tiles stay near-square and areas stay comparable at a glance.

Folders

Plain nested rectangles, one level at a time, for when the treemap is too dense to read.

Sunburst

Radial. Depth reads as distance from the centre, which keeps deep trees legible.

Flame

An icicle layout. The fastest way to find one deep, expensive path.

Bubbles

Circle packing. Emphasises count and clustering rather than exact area.

Mind map

A radial tree. Shows how a directory is shaped, not how large it is.

Top sizes

A ranked list, scoped to here, to files anywhere, or to folders anywhere.

Age map

Coloured by last-modified age. Old and large is the best cleanup signal there is.

Nothing is deleted until you say so

This tool moves files, so the safety model is not a footnote. It is four steps, and you can stop after any of them.

Nothing is ever deleted except by commit, and everything commit can delete is described by a manifest that was written to disk before the first file moved.

Download Plumb

Version 0.1.0. Free and open source under Apache-2.0. Windows builds from source only.

Or build from source

Works on every platform, including Windows, and produces no quarantine flag.

$ git clone github.com/Karanjot786/Plumb
$ cd Plumb
$ cargo install --path crates/plumb-cli  # installs `plumb`

$ plumb scan ~/Downloads