1. Peter Larsen Red Hat Solutions Architect For FredLug,
October 2013
2. Introduction to Linux Basic Computer Architecture
Introduction to Operating Systems History of Linux and Open Source
Features of Linux How to get started
3. Basic Computer Architecture Power (PSU) Mother board CPU RAM
Hard drives Video Card
4. The CPU Executes all instructions Instructions are binary
(OP codes) Modern CPUs have multiple cores (more than one CPU on
the same chip) CPU speed is measured in hertz - how fast the heart
beat of the CPU beats
5. Memory Electronic storage of data Cannot persist without
power Fast! (but not the fastest) Nanoseconds to respond Must be
compatible with the motherboard (bus)
6. Mother Board Where it all comes together Components of the
computer connects via BUS connections on the MB Different MBs
support different BUS speeds Some come integrated with video and
much more
7. Hard Drive Stores Data persistently Can be mechanical (hdd)
or electronic (ssd) Connects to a controller (SATA, PATA, IDE)
Controller is attached to or embedded in the motherboard Slow (>
1000 times slower than main memory)
8. The magic that makes it all work The Transistor
9. Logic Gates AND gateOR gate
10. How does it work? Flip-Flop basic electronic component of
computers Maintains a consistent state between messages (memory)
NOR gates (Not OR) are true only when both inputs are 0 (false)
Gates are basic electronic features implemented using transistors
(outside scope)
11. Adding Half adder take two bits and add them together XOR
and AND gates used XOR is true when only one or the other input is
true AND is true only when both are true Putting adders in serial
connections allows us to add many bits together A B C S 0 0 0 0 0 1
0 1 1 0 0 1 1 1 1 0
12. Full Adder Including the carry from a previous adder into
the result. XOR, AND and OR gates A B Ci Co S 0 0 0 0 0 0 0 1 0 1 0
1 0 0 1 0 1 1 1 0 1 0 0 0 1 1 0 1 1 0 1 1 0 1 0 1 1 1 1 1
13. Architecture
14. Machine (CPU) Language Machine language is easy for the
computer to understand HARD for humans Higher level computer
languages translate easier understood languages to computer OP
codes
15. Introduction to Operating Systems Hardware does nothing
without software The operating system is an abstraction layer
between your code and the hardware The hardware has no concept of
files, printers, network etc. - all of which is defined by the
Operating Systems Examples: Unix, Windows, Linux, VMS, DOS,
CP-M
16. The OS Layers
17. Defining devices, security etc.
18. The Linux Kernel
19. History of Linux and Open Source First version published by
Linus Torvalds in 1991 Licensed under GNU GPL in 1992 first Linux
Distributions appear 1994 version 1.x is released Red Hat releases
first version 1998 Major companies announce support for Linux (IBM,
Oracle, Compaq) 2003 First enterprise release of Linux 2012 Red Hat
becomes first company to cross $1 billion in revenue on Open Source
(not just Linux)
20. Why did it happen? Open Source started much earlier than
Linux Early/Mid 1980s Richard Stallman and a group of engineers
wanted a free version of Unix to use in universities. Proprietary
code and contracts prevented use of the systems to do what Stallman
wanted to do Established GNU, CopyLeft and FSF which lead to GPL
1.0 http://www.gnu.org/gnu/thegnuproject.html Open Source is about
FREEDOM not gratis (free as in beer) The freedom to share created
innovation and participation
21. Linux is just the tip of the ice berg Open Source existed
before Linux but GNU and Linux created a platform making Open
Source projects take off Apache Java Perl Python Postgresql Using
commodity hardware and free software, everyone can take part The
internet is the glue that holds the communities together
22. Software Repositories Early on working with Linux meant
custom compiling everything to install it including the kernel
Today's Linux distributions all use binary distributions of
software The binaries are stored on repository servers making it
very simple to install any software Software comes in packages such
as RPM and DEP Installing software on Linux is easier than on
Windows
23. Features of Linux Linux is just a kernel the core of the
operating system The kernel does nothing without software. The GNU
project provided most of the software needed to be compatitble with
Unix (commands like ls, ps, cd, mkdir are all from the GNU project)
Some prefer to call Linux GNU/Linux since this is more true to what
actually makes a basic Linux system run Linus Torvalds still
maintains control of the kernel and it's development Linux
dominates in most data-centers, in appliances and mobile devices.
Chances are you're running Linux already without knowing it!
24. Core features of any Linux system File systems Has a root
(named /) and directories under it. Directories may be mount points
to other file systems. Software is not aware of where data is
actually stored Lots of different file systems: ext2/3/4, ReiserFS,
XFS, vFAT, NTFS Everything is a file The concept of files goes
beyond storing data. Everything is represented via a file, such as
raw devices to which to OS communicates Even processes are seen as
files
25. Putting it all together Linux provides a base to run
advanced and high performing software on Open Source means you can
get it for free Linux supports older hardware because you can slim
down what you run, you can make it run with little memory and CPU
power of older hardware Tons of software written for Linux today.
Community participation makes Linux grow join the community!
26. More Core Features Processes A process is a unit that
executes code Some processes are part of the operating system When
your software runs, it becomes a process All processes have a PID
(Process IDentifcation) number Processes are owned by a user Linux
handles how to run many processes at the same time. It's not
unusual to have 200 processes at the same time
27. Features .... Security Multi User operating system. Linux
is designed to be used by more than one user at a time Everything
must run as a user Every system has a root user with UID of 0. This
super admin can bypass pretty much every security feature of the
system. NO ONE SHOULD RUN AS ROOT PERMANENTLY! File security allows
files to be kept private, shared with a few or shared with
everyone. Security defines rights to read, write and execute.
28. Features the interface Linux can be used with or without a
graphical interface Servers usually run without a GUI Users can
choose between many different types of GUI environments (window
managers) GNome, KDE, Sugar to mention a few Command Line consoles
local and remote
29. Features - Networking Linux did not become TCP compliant
until late in it's life. It was one of the many delays before
version 1 was released Today, Linux is used as the core in routers
and switches. It's modularity and highly customizable structure
makes it ideal for embedded devices Linux supports more than IP
networking but it's by far the most used Linux is ideal for
firewalls and complex network usage
30. How to get started For end users, Linux provides all the
features we use computers for: Email, Web browsing, graphical
design, movie making/editing, photo management, 3D design, Music
and much more Robust and secure OS No need to be grand techie to
get started (this did not use to be the case) How do I run my
Microsoft/MAC program on Linux? Short answer: you don't Long
answer: Find the same program made for Linux or something that
provides the same features
31. Distributions The first step is to pick a distribution
Distributions are released collections of already compiled and
configured Linux systems. Without distributions, you'll have to be
an IT master to configure a system to run Linux There are many
flavors of Linux distributions: Ubuntu, Fedora, Debian, Arch, DSL,
CentOS, Red Hat, SuSE in facts hundreds of distributions exit Where
to begin: http://distrowatch.org
32. User Groups You're already here so we can skip this :)
Networking learning from peers helps you getting over the hurdles
that you will run into Linux is all about the community become part
of it, attend user group meetings, use IRC, Mailing lists etc. to
make Linux better. Without an active community, Open Source does
not work. A great place to work on getting better at public
speaking
33. IRC Internet Relay Chat Has been around since the mid
1980'ies Group chat online Being able to talk to 10s or hundreds at
the same time, is not only fun but a great way to learn and
exchange ideas Text based old school! XChat and irrs are popular
programs on Linux to use for IRC freenode.org is the IRC server for
anything open source
34. Mailing Lists Web sites, Mailing lists, IRC are ways of
communication Mailing lists are email based communication where you
send emails out to all subscribers. It allows a community of people
to communicate easily together via email UUNET is dead no more,
where's the beer? Go to http://calypso.tux.org/ to sign up for our
mailing list http://www.meetup.com/fredlug http://fredlug.info
35. Questions? Start from: What do you want to do? Once you
find your answer, there is software out there to help you do that!
You do not have to be super technical to make use of Linux A little
bit of knowledge helps tremendously
