1. Unix/Linux basics 0000 Operating systems lab Gergely Windisch
room 4.12

2. About the class - organization
14 weeks - 4 hours / week
Tuesdays from 15:20 to 18:40
Attendance is not optional (surprise, surprise)
except for the 6th of April
and when someone really does not want to come
Grading
homework - necessary for taking the exam
exam - grade is given based on the score 2

3. About the class - topics
We are going to cover
linux basics
commands
files, directories
permissions
user management
program installation
shell scripting
GUI
services
for details, see unixclass.doc 3

4. Project assignment
The students should create a small infrastructure consisting of at least three machines
The goal is to have an application server and a separate database server set up, and then use the client to install a service to the application server.

5. Project assignment
Three machines
Client (any desktop linux or unix will do)
Application server (web or something like that)
Database server
Application server
Should serve static and dynamic content - apache, php etc.
install some freeware php application - wiki, cms, forum engine, blog, joomla, drupal - your choice
needs to be accessible via ftp from the client machine
should run *sql (my~, pl~, postgre~)
will serve all the data for the application server
needs to have ftp access
needs to have a firewall that rejects direct access from every machine except for the application server
The servers should be console only (no GUI)
All the operating systems need to be different, at least one needs to be unix
For example: Fedora for the client, opensolaris for the app server, Solaris for the DB

6. Project assignment What to hand in Important dates
The virtual machines (DVD, USB stick, whatever)
Documentation
3-5 pages
summary of the systems, usernames and passwords
screenshots from the working systems
description of the problems you have ran into (if any)
Important dates
23th of February - list of the systems to be used
4th of May - due date

7. Unix - the beginning Operációs rendszer 1969 - Bell laboratories
Ken Thompson, Dennis Ritchie, Brian Kernighan (and many others)

8. Unix systems
Single UNIX Specification - defines what needs to achieved to be called Unix
IBM AIX ( November)
HP-UX (HP-UX 11i v3 Update April)
Mac OS X (v10.5)
Sun Solaris (now called Oracle) (10 5/ May)

9. Unix-like system
Systems without SUS certification can only be called Unix like
BSD (Net-, Free-, Open-)
Linux (Debian, Slackware, Gentoo, Ubuntu stb.)

10. Solaris Why Unix? (and not windows) Why Unix? (and not Linux)
oh please…
Why Unix? (and not Linux)
Stability, advanced technologies, reliability, plannability (eg. zfs, DTrace)
Why Solaris?
The only one that runs on Intel architecture :)
Solaris 10 vs. OpenSolaris

11. Solaris vs OpenSolaris
Closed development
Stable
Enterprise level support
CDE graphical interface
OpenSolaris
Developed since open soure
"test bed" of Solaris

12. OpenSolaris
Sourcecode
Community
Distribution

13. Other OpenSolaris distributions
SXCE (SOlaris Express COmmunity Edition) - The original OpenSolaris distributions, made by Sun (now Oracle)
Schillix - the first.
Belenix - interesting, it has more GUIs, not just gnome.
NexentaCore - Cross between Ubuntu and OpenSolaris. Has all the GNU tools, apt-get package management, uses the ubuntu repository install software.
keresztezése. Benne van a teljes GNU eszközkészlet, apt-get csomagkezelő, az ubuntu repositoryt használja a telepítéshez. It also has zfs, is able to create snapshots making it easy to restore the previous states after an upgrade that has gone badly
MilaX: Nice little distribution. Aims for lightness.

14. Multiuser, multitask operting system
Unix history
It was created around the 70’s for mini computers. It has spread to the mainframes, workstations and then to personal computers
Simplicity was always an aim
The kernel was written in C (almost from the beginning) -> new
The many flavors of Unix and the incompatiblity that came with it is still around
Multiple unix versions: good, because competition enhances  there is no one accepted solution (incompatiblity)
Standardization work, multiple standards (the important is „what”, not „how”)
Commercially avalable Unix versions: Sun/Solaris, HP/HP-UX, IBM/AIX
Interesting: Mac OS X (BSD based)
Multiuser, multitask operting system

15. Linux Born in 1991– Linus Torvalds – x86
Started life as a terminal app for minix
Nowdays an alternative to Unix and Windows systems
Linux is not Unix, but similar
Unix like in appearance and programming API, different under the hood
The kernel is not held by one company but is developed by the community (with centralized management - Linus)
The code base is developed by the community
Wide spectrum of supported hardware architectures
There are some pioneer solutions, but there are also some weak spots compared to the „big” Unix versions (thread management in the 2.4 kernels for example)

16. Linux - distributions Linux distributions
„A Linux distribution (also called GNU/Linux by some vendors and users) is a member of the family of Unix-like software distributions built on top of the Linux kernel. Such distributions (often called distros for short) consist of a large collection of software applications such as word processors, spreadsheets, media players and database applications. The operating system will consist of the Linux kernel and, usually, a set of libraries and utilities from the GNU project, with graphics support from the X Window System. „ - Wikipedia
ldt.svg

17. Linux – distros (cont’d)
Even more colorful than unix
free and commercial as well
Most important commercial versions: RedHat and Suse
Free versions: Debian and co. (debian based), Fedora (RedHat based) and openSuse
Live CD try without installation
Knoppix: (Debian GNU/Linux)
Demolinux: (Mandrake)
More at:

18. Useful links http://www.hup.hu – Hungarian Unix Portal
Only in hungarian  for those of you who are interesten in the language
– Place of the linux kernel
– home of practically all the distributions

19. Where can I practice? Downloading linux:
en.opensuse.org,
VMWARE pre-built images: ectory/cat/45 19

20. Where can I get help? Everywhere!
The Hungarian Unix Portal: (again, for the eager minded)
Linux Knowledge Base and Tutorial:
Linux Shell Scripting Tutorial: 20

21. The graphical world… Distributions RedHat (www.redhat.com)
Ubuntu (
Debian (
Slackware (
Mandriva (
Suse (opensuse.org)
Let’s look at some of them

22. Linux basics
Linux is like Unix – API and the command line is unix compatible
As far as we get into the subject, all the distros are the same
Makes no difference which one we install

23. Linux basics (cont’d)
Multiuser: we do not rule the whole machine – just one session (many concurrent users)
Authentication before being able to do anything – user + password
System access is restricted – we can only modify those to which we have the permissions
Simple users cannot change (break) the system (for that would affect others)!

24. Because of the multiuser environment, linux is somewhat different to other pc operating systems: one machine, multiple terminals. Still apparent today: virtual console
Text based mode (shell) and graphical interface (X)
GUI is spreading like mushroom after the rainy season - but the main interface for setting the system up is still the console.
Terminal access via TCP/IP, earlier it was via RS-232 (serial port)
In a PC based desktop solution the machine and the view isn’t separated, however it is still separated underneath (modularity)

25. root user
Every OS needs a superuser who can access everything, set things up
In Unix, the role is called root. Root has total control over the machine
There can only be one root, it’s task cannot be given to multiple users
Possible solutions:
sudo, RBAC (hasn’t really caught on)
Security Enhanced Linux

26. Install'em We will be using Vmware workstation New virtual machine
Player, server works just as well
New virtual machine
choose type
specify hardware
specify install media
We have a whole bunch, try them all