Disk Visualization

The Linux tool Baobab uses a few normally unorthodox methods to show disk usage. It uses a radial space filling tree as a main view, and also a tree map. Let's see how these concepts are applied.

Radial Space Filling Tree

A simple way of figuring out graphically the disk usage of my /usr directory.

This is similar to the color wheel except with no spacing between sections. The top folder is the center section, and each ring sector away from the center is one directory down into the tree. Each ring is divided into sections representing each folder belonging to the parent sector.

The visualization is powerful because it shows how children directories sprout off of the parent directories. Also, the scale of the children in the grand scheme makes sense since it is constrained within the angular bounds of the parent sector.

In this example:

/usr/              (center)
     share/        (first ring, highlighted sector)
           doc/    (second ring, dark red sector on the right)

The size of the ring section indicates how much disk is dedicated to that folder. /usr/share is about half the first ring, so it contains about half of all disk usage of the folder /usr.

Treemap

The treemap version. From left to right: /usr/share (blue), /usr/lib (olive), /usr/src (brown), /usr/bin (lime), etc.

Either visualization shows rather easily that my /usr/share directory is the cause for the size of the /usr directory.

Radial Space Filling Tree

I've been continuing work with my color wheel using radial space filling trees, inspired in part because of DocBurst. I've modified the original source code to allow multiple levels of rings, though only three are seen here (the center circle is considered a segment, but I set it to the background color). Children sectors in the ring are constrained to the angle bounds of its parent.

Further steps include click detection on segments based to select different segments, and extracting a child segment to form a new color wheel.