GoboLinux

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GoboLinux is a Linux distribution whose most salient feature is its reorganization of the filesystem hierarchy. Rather than following the Filesystem Hierarchy Standard like most Unix-like systems, under GoboLinux each program has its own subdirectory tree, where all of its files (including settings specific for that program) can be found. According to the GoboLinux developers, this results in a cleaner system based on the filelayout level.^[1]

Contents 1 Overview 2 The GoboLinux hierarchy 3 Compile 4 Differences between GoboLinux and traditional distributions 4.1 File system 4.2 Symlinks 4.3 Boot system 5 Releases 6 Ports 7 References 8 External links

[edit] Overview

The GoboLinux hierarchy is a radical departure from the filesystem hierarchy traditionally employed by most Linux (and UNIX-like) operating systems, where specific types of files are stored together in common standard subdirectories (such as e.g. bin and man), and package managers are used to keep track of what file belongs to which program. In GoboLinux, files from different programs are separated into different respective subdirectories. While in GoboLinux types of files are also separated into subdirectories, these in turn sit inside their programs' subdirectories. The makers of GoboLinux say that "the filesystem is the package manager", and the GoboLinux package system uses the filesystem itself as a package database. ^[2] This produces a more straightforward, less cluttered directory tree. GoboLinux uses symlinks and an (optional & cosmetic) kernel module called GoboHide to achieve all this while maintaining full compatibility with the traditional Linux filesystem hierarchy.

The GoboLinux hierarchy has additional benefits, e.g. it removes some distinctions between similar traditional directories (such as the executable locations /bin, /usr/bin, and /usr/local/bin). GoboLinux designers claim that this results in shell scripts breaking less often than with other Linux distributions. GoboLinux also allows the user to have different versions of the same program installed concurrently (and even run them concurrently). Furthermore, the package management index can never get out of sync, as references to nonexisting files simply are broken links, and thus inactive. GoboLinux's filesystem changes have also allowed other innovations, such as an entirely new boot system that does not use System V or BSD style init systems.

[edit] The GoboLinux hierarchy

The design of GoboLinux is influenced by earlier systems such as NEXTSTEP, AtheOS and BeOS, which adopted original filesystem structures while still maintaining a considerable degree of compatibility with Unix. At the root of the GoboLinux tree, there are six directories: Programs, Users, System, Files, Mount and Depot. The contents of each are described below.

• /Programs/ - This directory contains one directory for each program installed in the computer. Each program's directory, in turn, contains one or more version directories, and optionally, Settings and Variable subdirectories. Examples of paths under programs are /Programs/Bash/3.0/bin/bash and /Programs/Xorg-Server/Settings/X11/xorg.conf.
• /Users/ - This directory contains users' home directories, so a userid named "harley" would have a home directory of "/Users/harley".
• /System/ - Crucial system files. Most are managed by system applications (for example, /System/Settings/passwd) and GoboLinux scripts (for example, /System/Links).
  • Links/ - Contains "links" directories that index the files under /Programs.
    • Environment/ - Links to environment files. These are compiled into a Cache file and loaded by the shell, allowing programs to register their own environment variables.
    • Executables/ - Contains links to files from the programs' bin and sbin directories.
    • Headers/ - This directory contains links to files from the programs' include directories.
    • Libraries/ - Links to files from the programs' lib directories.
    • Manuals/ - Contents of manuals and info directories.
    • Shared/ - Links to files from the programs' share directories.
    • Tasks/ - Links to the programs' boot tasks from their Resources/Tasks directories.
  • Settings/ - Configuration files and links to files from the programs' Settings directories.
    • BootScripts/ - Scripts used during system boot. This is a symlink to Settings/BootScripts/ under /Programs/BootScripts.
  • Variable/ - Multi-purpose log, temporary, transient and spool files.
    • tmp/ - Temporary files.
  • Kernel/ - Kernel-related directories.
    • Boot/ - Programs and configuration files used during operating system bootstrap. This is where the kernel image and bootloader configuration files are located.
    • Devices/ - Device files (managed by Udev).
    • Modules/ - Contains the various kernel modules, organized by the kernel release.
    • Objects/ - Provides a view of the kernel's device tree (introduced with the sysfs filesystem in the kernel 2.6 series).
    • Status/ - Kernel status files (managed by the proc filesystem ).
• /Files/ - Files hold structured data that are used by programs but that are not part of the programs themselves. Those files are usually stand-alone entities, like fonts, codecs and plugins (and as such, do not require package management). Additionally, applications may define subdirectories of their own to store site-specific data — Compile, the GoboLinux package compilation front-end tool, uses it.
• /Mount/ - mounting point for additional local or remote filesystems. Common subdirectories are CD-ROM, Floppy and Zip.
• /Depot/ - repository for users' files. This repository is meant to be organized as the user sees fit. No subdirectories of /Depot are considered part of the standard GoboLinux hierarchy.

[edit] Compile

Compile, introduced in 011, downloads, unpacks, compiles and installs source tarballs with a single command (such as "Compile foo") using simple compilation scripts known as "recipes"^[3].

Parallels of comparison^[4] have been drawn between GoboLinux's Compile and Gentoo's Portage system (which is, itself, based upon the FreeBSD Ports collection), which accomplishes the above actions with scripts known as "ebuilds". However, unlike Portage (which is made for a traditional, FHS-compatible filesystem hierarchy), Compile extends the capability of GoboLinux's distinctive filesystem hierarchy into the area of package management. Thus, in GoboLinux, the filesystem is the package manager, so to speak (see "The Ideas Behind Compile"^[5]).

Before Compile was released, a third-party port of Gentoo's Portage system to GoboLinux was discussed at Gentoo's official forums and then developed as a Sourceforge project under the name GoboPortage.^[6][7]

Among Compile's other features:

• It uses the projects' own download sites: the distribution's repository (or one of its mirrors) is only used for downloading recipes. Recipes may be downloaded on-the-fly or in batch.
• It uses minimalistic and declarative-oriented compilation scripts: typical "configure; make; make install" software can be scripted in two lines, greatly easing maintenance.
• It supports GoboLinux-style dependencies: software compiled "by hand" by the user is taken into account by the detection mechanism.
• It is path-agnostic by design: also works in a Rootless^[8]-GoboLinux installation, ie, inside a $HOME directory of any other distribution.

[edit] Differences between GoboLinux and traditional distributions

[edit] File system

In the GoboLinux hierarchy, files are grouped by their functional category in an index-like structure using symbolic links, rooted at /System/Links: all executables are accessible under /System/Links/Executables, all libraries are accessible under /System/Links/Libraries and so on. This eliminates many traditional distinctions in the Filesystem Hierarchy Standard, such as the distinction made between non-essential files stored in /usr and essential, emergency files stored directly in subdirectories of the root directory. The developers maintain that, although these distinctions were once very useful, they are no longer necessary in their radically different, modern environment.

[edit] Symlinks

There are symbolic links relating most of the usual Unix directories to the GoboLinux tree. Therefore, one can find directories such as /etc, /var/log and /usr/bin in the expected places. These symbolic links point to the functional equivalent under /System/Links, so that crucial pathnames such as /bin/sh and /etc/passwd are resolved correctly. These compatibility directories are concealed from view using a custom kernel modification called GoboHide — this modification, which implements support for hidden files in Linux, is used for aesthetic reasons only and is optional.

[edit] Boot system

Unlike most Linux distributions, GoboLinux uses neither a BSD nor a System V initialization procedure, using instead a procedure specific to GoboLinux. At /System/Settings/BootScripts there are a few files that command the entire boot procedure: BootUp and Shutdown run at system boot and shutdown, respectively; additionally, it is possible to define "runlevel" scripts to specify different ways the system can be initialized (for example, Single for single-user, Multi for multi-user, Graphical for boot into graphic mode, and so on.) and control that from the boot loader menu. The /System/Settings/BootOptions file separate site-specific settings from the rest of the scripts. Application-specific tasks can be found at /System/Links/Tasks and called by the boot scripts.

[edit] Releases

Releases are numbered using the octal base system. According to the authors, it was chosen because it keeps the typical leading zero present in many free software version numbers (since a leading zero is the indicator for octal numbers in the C language), and is a play on the "version numbers race" that happened among Linux distributions around 1999: when read as decimal numbers, octal numbers will cause a deterministic "version bump" each eight releases. Up to 013, GoboLinux made no "point releases", to avoid the implication that some releases were more stable than others. This tradition was broken with 014.01, an update of 014 focused on bug fixes.

• 014.01^[9] - March 30, 2008: an update of 014, featuring bug fixes and some package updates.
• 014 - December 31, 2007: new stable release, featuring package updates, bug fixes and new versions of the GoboLinux management tools.
• 013 - November 2, 2006: introduced Listener, a tool for listening on filesystem events and assigning actions to be performed automatically.
• 012 - June 6, 2005: introduced Manager, a graphical system management tool.
• 011 - June 7, 2004: introduced Compile, the GoboLinux package compilation tool.
• 010 - January 7, 2004: added a graphical installer accessible through the live CD desktop environment.
• 007 - October 22, 2003: added a per-package metadata directory called Resources.
• 006 - May 9, 2003: introduced GoboHide, adopted sandboxed installation of programs.
• 005 - 2003: first public release published online.
• Releases prior to 005 were used by the initial group of developers only.

[edit] Ports

As of March 2006, Gobolinux is officially made for the i686 only, and the porting to i386 is domain-specific (thus, incomplete). However, in 2003, Hisham Muhammad, the head developer of the Gobolinux project, wrote a "Quick-and-Dirty Porting Guide"^[10] for those who would wish to port the distribution to the PowerPC platform (among other architectures). He is also working on a port by himself.^[11] Ports have been made to embedded architectures, such as ARM and SuperH, which were easily achieved after Bootstrap,^[12] a tool developed especially to automate new ports.

[edit] References

[edit] External links

• GoboLinux at DistroWatch
• GoboLinux review at Linux.com
• GoboLinux website

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