# Disk Usage Analyser Manual

## Introduction

Disk Usage Analyser is a graphical, menu-driven application to analyze disk usage in any MATE environment. Disk Usage Analyser can easily scan either the whole filesystem tree, or a specific user-requested directory branch (local or remote).

It also auto-detects in real-time any changes made to your home directory as far as any mounted/unmounted device. Disk Usage Analyser also provides a full graphical treemap window for each selected folder.

## Getting Started

Disk Usage Analyser can be started in three ways:

- from MATE menu Applications Accessories;

- from a terminal window;

- from Caja "Open with..." ;

If you want to start Disk Usage Analyser from a terminal window, just type:

`mate-disk-usage-analyzer <full_path_to_a_directory>`, then press Return.

If launched from MATE menu, Disk Usage Analyzer starts and remains in a stand-by state, waiting for user action.

When you start Disk Usage Analyser from the MATE Menu, the following window is displayed.

### Disk Usage Analyser Window

Shows Disk Usage Analyser main window. Contains menubar, display area, scrollbars, and statusbar.

The user can then:

- start a full filesystem scan;

- select a specific local directory branch to scan

- select a remote server and folder to scan

- set preferences

## Usage

### Full filesystem scan

To start a full filesystem scan select Analyser Scan Filesystem from the menu, or press on the Scan Filesystem toolbar button.

When the scanning process ends up, you will get the full tree of your filesystem, like the one in the next Figure.

#### Disk Usage Analyser Full filesystem scan

Shows Disk Usage Analyser full filesystem scan window. Contains menubar, display area, scrollbars, and statusbar.

When you run a full filesystem scan, Disk Usage Analyzer window will start drawing the tree as soon as the thread starts scanning the filesystem. If any large partition is mounted on the filesystem, that will be scanned too.

Disk Usage Analyzer will display sizes in the directory tree as allocated space. This means that the displayed sizes refer to the actual disk usage and not to the apparent directory size. If you want to view the apparent file size, uncheck View Allocated Space .

Disk Usage Analyzer will not count the /proc dir, nor any file size that is not related to a "plain" file, so symlinks, character blocks, device blocks will not be part of the directory size.

Hard-links are managed in a different way: this first hardlink is counted as a normal file, while the subsequent links to the same inode device are not counted in the total, but highlighted in the right-hand column of the window.

### Single folder scan

To start a single folder scan select Analyzer Scan Folder... from the menu, or press on the Scan Folder toolbar button.

### Remote scan

If you need to scan a remote server-folder, just click on the toolbar icon Scan Remote Folder or select Analyzer Scan Remote Folder from the menu and you will get the following dialog box. Disk Usage Analyzer can connect to a server through ssh, ftp, smb, http and https.

#### Disk Usage Analyzer Remote folder scan

Shows Disk Usage Analyzer remote folder dialogue window.

## Preferences

To change the Disk Usage Analyzer application preferences, choose Edit Preferences.

### Disk Usage Analyser Preferences Window

Preferences window

### Select devices to be scanned

In the first part of the Preferences window, all detected mounted devices are listed. Click on the checkbox to include/exclude the partition into the filesystem scanning operations.

The device mounted on "/" cannot be excluded from the scan.

### Enable monitoring of home

If this option is checked, Disk Usage Analyzer will constantly monitor any external changes to home directory and warn the user if a file is added/removed.

## Treemaps

Treemap concepts have been developed by Ben Shneiderman in the '90s. Read his vision on treemaps.

### Disk Usage Analyser Treemap Window

Treemap's theory. Shows 2 treemap diagrams

Figure shows an example of treemap's theory. Each node (as shown in the tree diagram) has a name (a letter) and an associated size (a number). The size of leaves may represent for instance the size of individual files, the size of non-leaf nodes is the sum of the sizes of its children.

The treemap is constructed via recursive subdivision of the initial rectangle. The size of each sub-rectangle corresponds to the size of the node. The direction of subdivision alternates per level: first horizontally, next vertically, etcetera. As a result, the initial rectangle is partitioned into smaller rectangles, such that the size of each rectangle reflects the size of the leaf. The structure of the tree is also reflected in the treemap, as a result of its construction. Colour and annotation can be used to give extra information about the leaves.

Treemaps are very effective when size is the most important feature to be displayed.

## Ringschart

Ringschart is a graphical representation of the disk usage by a concrete folder. When launching the application, it is notified the usage of the file system as it can be seen in the next figure:

### Disk Usage Analyser showing a ringschart with the file system usage

After launching the application, it is showed the file system usage. Graphical representation on the right.

When you start scanning a folder, the tree of subfolders is created and listed on the left side. Each row contains information for the name, how much space it is taking up (percentage and size in KB, MB or GB) and the number of items (adding files and directories). When this process ends up, the Ringschart is drawn on the right side. If you stop it before it has been completed, only a partial representation is done based on the directories whose usage was computed.

### Disk Usage Analyser showing a ringschart with the usage of a folder

After scanning a folder.

The Ringschart is composed of a set of nested rings around a central circle. This circle symbolises the root folder of the partial tree (that is, the folder that the user has selected for scanning). Each ring represents a level in the partial tree, so i.e. the subfolders of the root folder will be represented in the first ring, and deeper levels in the tree correspond to outer rings in the chart. Each subfolder is represented by a sector of the ring, its angle being proportional to the size of the folder's contents, and painted with a different colour to ease visualisation. Up to five levels can be drawn; in case that a folder in that last fifth level contains even more subfolders, this situation will be pointed by the presence of a black curve close to the edge of that folder's ring sector. When a folder with no further subfolders is selected to be the root of the partial tree, only the inner circle will be drawn. When the mouse pointer hovers one of the folders in the graphic, it will be highlighted and a tooltip will appear with information about its name and size. If there are any subfolders, small grey tooltips will appear, indicating their names. It's possible that not all of the subfolders' names are displayed, to avoid overlappings.

You can go up and down the rows in the list (optionally expanding those with subfolders), the graphic representation will change using the selected folder as the root of the partial tree to be represented. The folders can also be navigated from the ringschart itself. If you click with the left button of your mouse inside a folder, you'll move deeper by setting the root of the graphic to that folder. If you press the middle button (no matter the place as long as you click inside the ringschart frame) you'll get the opposite behaviour, going back one step in the hierarchy.

The percentage of its parent's radius that is used by a given folder is directly proportional to the relation between its own size and its parent's. It's easy to understand that the size of a folder is equal or smaller than its parent's. Although only directories are shown in this graphical representation, files are taken into account to calculate the amount of space occupied by folders.