Linux Basics

Linux Basics

Michael Faath, Martin Lowinski

TumFUG

10. November 2011

1 of 33 Michael Faath, Martin Lowinski Linux Basics

Linux Basics

Outline

1 Linux history

2 Linux distributions

3 Linux insight

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Linux Basics

Skill-Level

• Ever used linux?

• Installed Linux?

• What is a distribution?

• XUbuntu? Debian? Red Hat? Fedora? Gentoo? Arch Linux?

• cat my movie collection | grep Hackers

• chmod 777 *

• ./configure && make && make install

• make && make modules install

• sed -i ’s/teh/the/g’ thesis.tex

• LPIC?

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Linux Basics

Skill-Level

• What do you want to know?

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Linux Basics

Linux history

Outline

1 Linux history

2 Linux distributions

3 Linux insight

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Linux Basics

Linux history

Unix / GNU

UNIX / GNU

• 1960s-1970: UNIX

• 1983: Richard Stallman started GNU(Free UNIX-like OS)

• 1987: MINIX by Andrew S.Tanenbaum

• 1991: GNU nearly complete // Kernelmissing

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Linux Basics

Linux history

Linux

Linux

• MINIX only for 16Bit-Systems

• Linus Torvalds programmed a terminalemulator to access the UNIX-Server ofhis university

• wanted to take advantage of his newPC with an 80386 processor

• therefore OS independant

• used GNU C compiler on MINIX

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Linux Basics

Linux history

Linux

Torvalds on comp.os.minix

Hello everybody out there using minix -

I’m doing a (free) operating system (just a hobby, won’t be big andprofessional like gnu) for 386(486) AT clones. Th is has been brewing sinceapril, and is starting to get ready. I’d like any feedback on things peoplelike/dislike in minix, as my OS resembles it somewhat (same physical layout ofthe file-system (due to practical reasons) among othe r things).I’ve currently ported bash(1.08) and gcc(1.40), and things seem to work. Thisimplies that I’ll get something practic al within a few months, and I’d like toknow what features most people would want. Any suggestions are welcome, butI won’t promise I’ll implement them :-)

Linus (torvalds@kruuna.helsinki.fi)

PS. Yes it’s free of any minix code, and it has a multi-threaded fs. It is NOT

portable (uses 386 task switching etc), and it probably never will support

anything other than AT-harddisks, as that’s all I have :-(.

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Linux Basics

Linux history

Linux

Open Source

• Free as in freedom, not as in free-beer

• Sourcecode available

• Free to copy

• Free to change / redistribute

• Free Software Foundation and Open Source Initiative (OSI)

• Licenses: GPL, BSD, Apache, Beerware

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Linux Basics

Linux history

Linux

Unix timeline

10 of 33 Michael Faath, Martin Lowinski Linux Basics

Linux Basics

Linux distributions

Outline

1 Linux history

2 Linux distributions

3 Linux insight

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Linux Basics

Linux distributions

What’s a distribution?

What’s a distribution?

Important

Linux is just the kernel, nothing more.

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Linux Basics

Linux distributions

What’s a distribution?

What’s a distribution?

Distributionz. B. Debian, Red Hat, SUSE, Mandriva

Proprietäre Programme(z. B. Adobe Reader, Grafikkartentreiber)

Freie Programme(z. B. KDE, OpenOffice, Apache)

Linux-KernelD

istr

ibu

tio

nse

igen

eP

rog

ram

me

(z. B

. zu

r Konfigura

tion,

Inst

alla

tion w

ie Y

ast

, m

cc) Hand-

bücher

Support(per Telefon,E-Mail o. ä.)

To build a distribution you need... (in general)

• the linux kernel,

• some GNU stuff,

• a package management system

• and applications

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Linux Basics

Linux distributions

What’s a distribution?

Overview

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Linux Basics

Linux distributions

Distro Guide

Where are the differences?

Guide to your favourite Linux distro:

• Installtools (LFS vs. Ubuntu)

• Hardware compatibility (x86, devices, ...)

• Documentation / Support (active community, books)

• Principles (live, free software, KISS)

• License (GPL, DFSG)

• Package Layout (meta vs. binary)

• Help: Linux distribution chooser

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Linux Basics

Linux distributions

Package Management Systems

Package Management Systems

• Software repository

• Verify checksums / signatures of packages

• Updating

• Uninstalling

• Dependencies

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Linux Basics

Linux distributions

Package Management Systems

Types and Examples

• Binary packages

deb Debian package - dpkg, apt, aptitude, ..RPM RPM Package Manager - rpm, yum, ...

• Source packages

ebuild How to retrieve, compile, and install a packagein Gentoo’s Portage system - emerge

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Linux Basics

Linux insight

Outline

1 Linux history

2 Linux distributions

3 Linux insight

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Linux Basics

Linux insight

Boot

Boot

Typical boot sequence:

1 BIOS

2 MBR

3 Boot Loader

4 Kernel (+initrd)

5 init

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Linux Basics

Linux insight

Shell

Shell

• {Shell, Bash, zsh, screen, ksh}• Command line interface

• Powerful tool

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Linux Basics

Linux insight

Filesystem Hierarchy Standard (FHS)

Filesystem Hierarchy Standard (FHS)

• defines main directories and contents

• version 2.3 (2004)

• /

• virtual file system

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Linux Basics

Linux insight

Filesystem Hierarchy Standard (FHS)

Filesystem Hierarchy Standard (FHS)

• static files

• variable files

• shareable files

• unshareable files

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Linux Basics

Linux insight

Filesystem Hierarchy Standard (FHS)

Directory structure I

• /bin

• /boot

• /dev

• /etc

• /home

• /lib

• /media

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Linux Basics

Linux insight

Filesystem Hierarchy Standard (FHS)

Directory structure I

• /bin (essential command binaries)

• /boot (bootloader files)

• /dev (devices)

• /etc (host-specific system-wide configuration files)

• /home (optional, user directories)

• /lib (kernel modules and dynamic librarys for /bin and /sbin)

• /media (optional, mount points for removable media)

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Linux Basics

Linux insight

Filesystem Hierarchy Standard (FHS)

Directory structure II

• /mnt

• /opt

• /root

• /sbin

• /srv

• /tmp

• /usr

• /var

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Linux insight

Filesystem Hierarchy Standard (FHS)

Directory structure II

• /mnt (optional, temporarily mounted filesystems)

• /opt (optional software packages)

• /root (optional, “home“-directory for the root user)

• /sbin (essential system binaries, for root user only)

• /srv (service-data)

• /tmp (temporary files)

• /usr (secondary hierarchy for read-only user data)

• /var (variable data)

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Linux Basics

Linux insight

Linux Kernel

Linux Kernel Layout

CPU Memory Devices

Kernel

Applications

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Linux Basics

Linux insight

Linux Kernel

Linux Kernel Structure

Hard-

ware I/O CPU Speicher Datenträger Netzwerk Peripherie

USB,PCI…RegisterInterrupts

MMU,RAM IDE,SATASCSI

EthernetWiFi

GPU,AudioTastatur,Maus

Linux-

Kernel Prozessor-

architekturspezifischer

Code

Bus-TreiberSpeicher-operationen

Disk-Controller-Treiber

Netzwerk-karten-Treiber

Benutzer-schnittstellen-

Treiber

InterruptsallgemeinerHardware-zugriff

Speicher-seiten-

Verwaltung

block-orientierteGeräte

virtuellesNetzwerk

abstrakteHI-Treiber

ZeitscheibenModuls

+Ereignisse

logischerSpeicher

logischesDateisystem

virtuellesNetzwerk

HI-Subsystem

Zeit-abstimmung

Geräte-Verwaltung

Speicher-planung

Netzwerk-zwischen-speicher

System-Sicherheit

Speicher-Auslagerung

Cache-Seitenverwalt.

ThreadsvirtuellerSpeicher

virtuellesDateisystem

Netzwerk-protokolle

ProzesseSystem-aufrufe

Speicher-zugriff

Dateisystem-zugriff

Netzwerk-zugriff

Benutzer-schnittstelle

Benutzer-

Modus

System-dienste

Anwendungen

System-dienste

System-dienste

System-dienste

System-dienste

Anwendungen Anwendungen Anwendungen Anwendungen Anwendungen

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Linux Basics

Linux insight

Linux Kernel

Linux Kernel Map

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Linux Basics

Linux insight

Linux Kernel

Linux Kernel

• version: 3.1 (“Wet Seal“ / “Divemaster Edition“)

• december: 3.2 (“Saber-toothed Squirrel“)

• license: GPL 2 / proprietary (BLOBs)

• monolithic kernel

• c / assembler

• 14.856.072 loc in 37.098 files

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Linux Basics

LPIC

• Linux Professional Institude

• Non-profit organization

• Vendor-independent certification for Linux systemadministrators and programmers

• Five year recertification policy

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Linux Basics

LPIC Levels

• LPIC-1 (“Junior Level Linux Professional“)• Exam 101 - Systemarchitectures, Partitioning, Devices, Drivers,

LFH, Package-Management, GNU-/Unix-Commands, ...• Exam 102 - Shell, Scripts, SQL, UI, Desktop, Network basics,

Security, ...

• LPIC-2 (“Advanced Level Linux Professional“)• Exam 201 - Kernel, Filesystem, Hardware, System

administration, Scripting, ...• Exam 202 - Network configuration, Mail/News, DNS, System

security, ...

• LPIC-3 (“Senior Level Linux Professional“)• Six exams

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Linux Basics

Thanks for your attention.

michael@faath.net – gpg: 0xA2586B21

martin@goldtopf.org – gpg: 0x35CDCCC4

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