path: root/src/admin/1_intro.xml

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<chapter label="1" id="introduction">
    <title>Introduction</title>
    <highlights><para>Welcome to the Adélie Linux 1.0 Administrator's Handbook.  You'll learn a lot about how to administrate your Adélie Linux computer.  We'll get started by looking at how Adélie Linux compares to other popular operating environments.  We will also review some of the software used that will feature in the chapters ahead.</para></highlights>
    <section id="compare">
        <title>Comparison of Adélie with other environments</title>
        <para>Adélie Linux is a Linux distribution focused on security, speed, reliability, and correctness.  Since it is based on the Linux kernel, it shares some common traits with other Linux distributions.  However, it has many unique facets as well.</para>
        <para>One of the defining differences of Adélie Linux is the commitment to run on many different hardware platforms.  The first comparison we will review is the hardware platforms that various environments support.</para>
        <table frame="all">
            <title>Hardware platforms supported</title>
            <tgroup cols="10" align="left" colsep="1" rowsep="1">
            <thead>
                <row>
                    <entry>Environment</entry>
                    <entry>DEC Alpha</entry>
                    <entry>ARM 32 / 64</entry>
                    <entry>HP PA-RISC</entry>
                    <entry>Intel 32 / 64</entry>
                    <entry>m68K</entry>
                    <entry>MIPS</entry>
                    <entry>PowerPC 32 / 64</entry>
                    <entry>S390x</entry>
                    <entry>SPARC64</entry>
                </row>
            </thead>
            <tbody>
                <row>
                    <entry>Adélie Linux</entry>
                    <entry>&cross;</entry>
                    <entry>&check; / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>&check; / &check;</entry>
                    <entry>Dev<footnote label="*" id="port_in_dev"><para>This port is in active development.  It is not available yet.</para></footnote></entry>
                    <entry>Dev<footnoteref linkend="port_in_dev"/></entry>
                    <entry>&check; / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>Dev<footnoteref linkend="port_in_dev"/></entry>
                </row>
                <row>
                    <entry>Alpine Linux</entry>
                    <entry>&cross;</entry>
                    <entry>&check; / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>&check; / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>&cross;</entry>
                    <entry>&cross; / &cross;</entry>
                    <entry>&check;</entry>
                    <entry>&cross;</entry>
                </row>
                <row>
                    <entry>Arch Linux</entry>
                    <entry>&cross;</entry>
                    <entry>&cross;<footnote label="$" id="arch_unofficial"><para>An unofficial port exists.</para></footnote> / &cross;<footnoteref linkend="arch_unofficial" /></entry>
                    <entry>&cross;</entry>
                    <entry>&cross;<footnoteref linkend="arch_unofficial" /> / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>&cross;</entry>
                    <entry>&cross; / &cross;</entry>
                    <entry>&cross;</entry>
                    <entry>&cross;</entry>
                </row>
                <row>
                    <entry>Debian GNU/Linux</entry>
                    <entry>&cross;</entry>
                    <entry>&check; / &check;</entry>
                    <entry>&check;<footnote label="&dagger;" id="deb_unofficial"><para>This is an unofficial Debian port and may be removed from Debian at any time.</para></footnote></entry>
                    <entry>&check; / &check;</entry>
                    <entry>&check;<footnoteref linkend="deb_unofficial"/></entry>
                    <entry>&check;</entry>
                    <entry>&check;<footnoteref linkend="deb_unofficial"/> / &check;<footnoteref linkend="deb_unofficial"/></entry>
                    <entry>&check;</entry>
                    <entry>&check;<footnoteref linkend="deb_unofficial"/></entry>
                </row>
                <row>
                    <entry>Fedora</entry>
                    <entry>&cross;</entry>
                    <entry>&cross; / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>&check; / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>&cross;</entry>
                    <entry>&cross; / &cross;</entry>
                    <entry>&check;</entry>
                    <entry>&cross;</entry>
                </row>
                <row>
                    <entry>FreeBSD</entry>
                    <entry>&cross;</entry>
                    <entry>&check; / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>&check; / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>&check;</entry>
                    <entry>&check; / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>&check;</entry>
                </row>
                <row>
                    <entry>Gentoo Linux</entry>
                    <entry>&check;</entry>
                    <entry>&check; / &check;</entry>
                    <entry>&check;</entry>
                    <entry>&check; / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>&cross;</entry>
                    <entry>&check; / &check;</entry>
                    <entry>&check;</entry>
                    <entry>&check;</entry>
                </row>
                <row>
                    <entry>Mac OS X</entry>
                    <entry>&cross;</entry>
                    <entry>&cross; / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>&cross; / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>&cross;</entry>
                    <entry>&cross; / &cross;<footnote label="#"><para>Mac OS X supported 32-bit and 64-bit PowerPC until 10.5.</para></footnote></entry>
                    <entry>&cross;</entry>
                    <entry>&cross;</entry>
                </row>
                <row>
                    <entry>Windows</entry>
                    <entry>&cross;</entry>
                    <entry>&cross; / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>&check; / &check;</entry>
                    <entry>&cross;</entry>
                    <entry>&cross;</entry>
                    <entry>&cross; / &cross;</entry>
                    <entry>&cross;</entry>
                    <entry>&cross;</entry>
                </row>
            </tbody>
            </tgroup>
        </table>
        <para>Next, let's compare the policies of these environments.</para>
        <table frame="all">
            <title>Policies</title>
            <tgroup cols="5" align="left" colsep="1" rowsep="1">
            <thead>
                <row>
                    <entry>Environment</entry>
                    <entry>Release cycle</entry>
                    <entry>Libre software</entry>
                    <entry>Proprietary software</entry>
                    <entry>Package manager</entry>
                </row>
            </thead>
            <tbody>
                <row>
                    <entry>Adélie Linux</entry>
                    <entry>Release every 18 months; support for 3 years</entry>
                    <entry>All libre licenses allowed</entry>
                    <entry>Not available</entry>
                    <entry>APK</entry>
                </row>
                <row>
                    <entry>Alpine Linux</entry>
                    <entry>Release every 6 months; support for 2 years</entry>
                    <entry>All libre licenses allowed</entry>
                    <entry>Non-libre firmware in core repositories</entry>
                    <entry>APK</entry>
                </row>
                <row>
                    <entry>Arch Linux</entry>
                    <entry>"Rolling"; no stable release</entry>
                    <entry>All libre licenses allowed</entry>
                    <entry>Non-libre software in core repositories</entry>
                    <entry>Pacman</entry>
                </row>
                <row>
                    <entry>Debian GNU/Linux</entry>
                    <entry>Release every 2 years; support for 3 years</entry>
                    <entry>All libre licenses allowed</entry>
                    <entry>Available in specific repository only</entry>
                    <entry>dpkg or apt-get</entry>
                </row>
                <row>
                    <entry>Fedora Linux</entry>
                    <entry>Release every 6 months; support for 13 months</entry>
                    <entry>All libre licenses allowed</entry>
                    <entry>Available in specific repository only</entry>
                    <entry>rpm or dnf</entry>
                </row>
                <row>
                    <entry>FreeBSD</entry>
                    <entry>Release every 2 years; support varies</entry>
                    <entry>All libre licenses allowed</entry>
                    <entry>Limited</entry>
                    <entry>pkg-ng, or compiled from ports</entry>
                </row>
                <row>
                    <entry>Gentoo Linux</entry>
                    <entry>Weekly snapshots; no stable release</entry>
                    <entry>All libre licenses allowed</entry>
                    <entry>Available only if user allows them</entry>
                    <entry>Portage</entry>
                </row>
                <row>
                    <entry>Mac OS X</entry>
                    <entry>Stable release every year; support for 2 years</entry>
                    <entry>BSD and MIT-style only; most GPL software not allowed</entry>
                    <entry>Most system components</entry>
                    <entry>App Store</entry>
                </row>
                <row>
                    <entry>Windows</entry>
                    <entry>"Rolling"; no stable release</entry>
                    <entry>All libre licenses allowed</entry>
                    <entry>All system components</entry>
                    <entry>Various</entry>
                </row>
            </tbody>
            </tgroup>
        </table>
        <para>Lastly, let's have a more technical comparison of these environments.</para>
        <table frame="all">
            <title>Technical differences</title>
            <tgroup cols="6" align="left" colsep="1" rowsep="1">
            <thead>
                <row>
                    <entry>Environment</entry>
                    <entry>Compiler and libc</entry>
                    <entry>Initialisation system</entry>
                    <entry>Shell environment</entry>
                    <entry>Desktop environment</entry>
                    <entry>Custom package support</entry>
                </row>
            </thead>
            <tbody>
                <row>
                    <entry>Adélie Linux</entry>
                    <entry>GCC, musl</entry>
                    <entry>OpenRC (default) or s6</entry>
                    <entry>Zsh (default) or others</entry>
                    <entry>KDE Plasma 5 and others</entry>
                    <entry>Yes</entry>
                </row>
                <row>
                    <entry>Alpine Linux</entry>
                    <entry>GCC, musl</entry>
                    <entry>OpenRC</entry>
                    <entry>BusyBox ash (default) or others</entry>
                    <entry>GNOME 3 and others</entry>
                    <entry>Yes</entry>
                </row>
                <row>
                    <entry>Arch Linux</entry>
                    <entry>GCC, glibc</entry>
                    <entry>systemd</entry>
                    <entry>Bash (default) or others</entry>
                    <entry>GNOME 3 and others</entry>
                    <entry>Yes</entry>
                </row>
                <row>
                    <entry>Debian GNU/Linux</entry>
                    <entry>GCC, glibc</entry>
                    <entry>systemd (default) or sysvinit</entry>
                    <entry>Bash (default) or others</entry>
                    <entry>GNOME 3 and others</entry>
                    <entry>Some</entry>
                </row>
                <row>
                    <entry>Fedora Linux</entry>
                    <entry>GCC, glibc</entry>
                    <entry>systemd</entry>
                    <entry>Bash (default) or others</entry>
                    <entry>GNOME 3 (default) or KDE Plasma 5</entry>
                    <entry>Yes</entry>
                </row>
                <row>
                    <entry>FreeBSD</entry>
                    <entry>Clang, FreeBSD</entry>
                    <entry>FreeBSD</entry>
                    <entry>Bourne shell (default) or tcsh</entry>
                    <entry>GNOME 2 or KDE SC 4</entry>
                    <entry>Yes</entry>
                </row>
                <row>
                    <entry>Gentoo Linux</entry>
                    <entry>GCC or clang, glibc or musl or uclibc</entry>
                    <entry>OpenRC (default) or systemd</entry>
                    <entry>Bash (default) or others</entry>
                    <entry>GNOME 3 and others</entry>
                    <entry>Yes</entry>
                </row>
                <row>
                    <entry>Mac OS X</entry>
                    <entry>Clang, FreeBSD</entry>
                    <entry>launchd</entry>
                    <entry>Bash (default) or tcsh</entry>
                    <entry>Aqua</entry>
                    <entry>Yes</entry>
                </row>
                <row>
                    <entry>Windows</entry>
                    <entry>Clang, Win32</entry>
                    <entry>Custom</entry>
                    <entry>PowerShell (default) or Bash</entry>
                    <entry>Win32</entry>
                    <entry>Yes, with proprietary software</entry>
                </row>
            </tbody>
            </tgroup>
        </table>
    </section>
    <section id="differences">
        <title>What sets Adélie apart</title>
        <para>The Adélie Linux operating environment has many features that make it stand out from other environments.</para>
        <section>
            <title>Libre software only</title>
            <para>The first, and most important, is dedication to only providing libre software.  What is "libre software"?  Simply put, libre software is software that gives power to you as a user, instead of giving power to the developer or a corporation.  Many proprietary software packages have long contracts (sometimes termed "license agreements" or "EULAs") that restrict what you can do with them.  Libre software allows you the right to use it in any manner you wish, and the right to be able to change it yourself if you find an issue with it.  For many, this may not seem important, since most people are not computer programmers and cannot actually change software themselves.  On the contrary, it is very important.  This allows those who are computer programmers, security researchers, and other interested parties to review the source code for errors.  If an error, defect, or security issue is found during a review, it can be rectified nearly instantly.</para>
            <para>This gives you an additional benefit: If the original developer of a proprietary software package no longer wishes to maintain it, they can discontinue it and take away your right to use it, even if you paid for it.  This is not possible with libre software.  The software that you use is yours to use for your entire lifetime.</para>
            <para>Many other environments, including most other Linux distributions, eventually give in to the pressure to ship non-libre software.  The Adélie Linux software packaging guidelines specifically prohibit non-libre software from being included in Adélie Linux.</para>
        </section>
        <section>
            <title>Package choice</title>
            <para>Another valuable feature of Adélie Linux for administrators is the ability to choose what package serves your environment best.  You are not forced to use a specific init system, shell, MTA, logging daemon, or other such systems.  Your system is yours, and you have the freedom to choose.  For instance, the APK package manager will automatically prompt you to choose an MTA from the provided MTA packages when you install a package that requires one.</para>
        </section>
        <section>
            <title>Stable versioning and release schedule</title>
            <para>Adélie Linux puts stability first.  Package versions are chosen from upstream stability guarantees, and are LTS releases where possible.  Security patches are prioritised over feature releases.  Adélie Linux has a predictable release schedule, with new major releases every 18 months, and minor releases provided for three years after each new major release.  There are three "release channels" for Adélie: "stable", "current", and "dev".  A "stable" channel is provided for each major version that will update your computer to each new minor release automatically.  The "current" channel will also automatically upgrade your computer to each new major version as it is released.  The "dev" channel provides a "rolling" style distribution, similar to Fedora Rawhide or Debian sid.</para>
        </section>
        <section>
            <title>Support for many platforms</title>
            <para>Adélie Linux supports many different hardware platforms, allowing you to truly use your hardware your way.  All Adélie Linux packages are tested on all tier 1 architectures before being released.  From your PowerPC/POWER workstation, to your dusty old Intel x86 notebook, to your ARM 64 tablet, you can ensure you are getting the most out of your computers by using Adélie Linux on them.</para>
        </section>
    </section>
    <section id="familiarising">
        <title>Familiarising yourself with Adélie</title>
        <para>Now let's briefly go over some of the essentials of day-to-day administration of an Adélie Linux system.  These will be covered with more depth in later chapters.</para>
        <section>
            <title>The shell environment</title>
            <para>The <firstterm>shell environment</firstterm>, also called a terminal or console, is an interface where you type commands in to a command processor (the <firstterm>shell</firstterm>), and view the results of the command on your screen.  Windows users may know this environment as a "Command Prompt".  The shell environment is an essential part of administrating any Linux system.  Adélie Linux is designed to make the shell environment easy to use while still providing you with the ability to view and edit nearly every detail about your system.</para>
            <para>The default interactive shell in the Adélie Linux system is the Z shell (zsh).  This shell has many unique and powerful features, but by default, it works very similar to the widely-used Bash shell.  When you start your shell, you will be greeted with a prompt similar to:</para>
            <para><prompt><replaceable>yourname</replaceable> on <replaceable>computer-name</replaceable> ~ %</prompt></para>
            <para>The prompt contains your username, the name of the computer you are currently logged in to, and your current directory.  The "~" represents your home directory, where your personal files and settings are stored.  This "~" will change as you move around the directories on your computer's hard disk.  For example, if you type <command>cd Documents</command> to change to the Documents directory in your home directory, your prompt will then show:</para>
            <para><prompt><replaceable>yourname</replaceable> on <replaceable>computer-name</replaceable> ~/Documents %</prompt></para>
            <para>Your computer's name is always shown to you in the prompt.  This way, if you connect remotely to another computer, you will easily be able to tell where the commands you type are running.</para>
        </section>
        <section>
            <title>Package management</title>
            <para>All software in Adélie Linux is provided to you in the form of <firstterm>packages</firstterm>.  A "software package" is a single distribution of computer software that fulfils a purpose.  For example, AbiWord, a word processor, is provided in the "abiword" package.  When you want to install or uninstall software from your computer, you add (to install) or delete (to uninstall) packages.</para>
            <para>Adélie Linux uses the <firstterm>APK</firstterm> package manager.  The APK package manager is very fast, and performs well even on computers with limited resources.  To install a package, you run <command>apk add <varname>PACKAGE</varname></command>, where PACKAGE is the name of the software.  To uninstall a package, you run <command>apk del <varname>PACKAGE</varname></command>.</para>
        </section>
        <section>
            <title>Service management</title>
            <para>Adélie Linux allows you to run software in the background, called "services" or "daemons".  These include network services (such as a Web server or print server), a task scheduler (also known as "<command>at</command>" and "<command>cron</command>"), automatic virus scanner, or any other useful background task.  By default, Adélie Linux uses a service manager called <firstterm>OpenRC</firstterm>.</para>
            <para>You can manage services using the <command>service</command> command.  For example, to restart the <command>lighttpd</command> service, you run <command>service lighttpd restart</command>.</para>
        </section>
    </section>
</chapter>