Advanced Operating Systems

1
Advanced Operating Systems
Tonga Institute of Higher Education
Lecture 4 Installation and Installing Programs
2
Installation in Linux

• There are many different versions of Linux.
  Unlike other commercial operating systems that
  are controlled by one company, Linux is free to
  distribute and use.
• So, in the Linux world, there is a situation
  unlike what occurs in the proprietary operating
  system world a number of companies,
  organizations and individuals have developed
  their own "versions" of the Linux operating
  system, known as distributions.
• There are versions of Linux that were developed
  to be installed on computers that receive heavy
  traffic. Some were developed to be used in
  networks were security is a priority. There are
  versions of Linux that are meant to be installed
  on top of an existing operating system like
  Windows so people can try out Linux under
  familiar conditions.

3
Which Linux is the best?

• Most PC users probably just need the everyday
  version. This kind of Linux has been widely
  available for some time now.
• Unfortunately Microsoft Corp., who makes its
  living selling people "ordinary" operating
  systems, have a lot to lose if Linux ever got
  popular with the masses. For this reason they
  have done everything in their power to "warn" the
  public that Linux is something that you probably
  don't want and don't need. But in reality, Linux
  is just as easily installed and supports just as
  wide a range of hardware as Microsoft Windows
  does.

4
Which Linux is the Best?

• Of all the distributions out there, and there are
  a lot, the most popular ones, with the easiest
  installation and maintenance are RedHat, SuSE,
  and Debian.
• RedHat Linux is probably the most popular and
  they have been the most successful. You can
  download their 'Personal' version for free from
  their website.
• They also have an 'Advanced Server' which costs
  around 500-1000 US, but Linux is Linux and
  you'll be able to do anything you need with the
  'Personal Edition'

5
The Install

• There are a couple of questions you need to ask
  yourself.
• 1. Do you have another operating system
  installed.
• 2. Do you want to continue to use it.
• If you want to keep an existing operating system,
  and install Linux as well, you will have what is
  known as a "dual-boot" system.
• That means that you have a PC that can use two
  different operating systems. The important thing
  is that you have the option to have both.

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Dual-booting

• To have to operating systems on your computer,
  you'll need two partitions at least.
• If you happen to have MS Windows you must
  repartition your hard drive to make room for
  Linux.
• You can either erase the drive and repartition a
  blank drive or you can attempt to repartition a
  working hard drive. Ideally, what was done in the
  "old" days was to install Windows in C and Linux
  in the D partitions.
• There are programs that can help you repartition
  a hard drive that only has one partition, but
  sometimes this might be dangerous

7
Installing

• If you have the right partitions, then you can
  pop in the CD you have and boot up your computer.
  
• Your computer probably supports booting from the
  CD-ROM. In this case, Linux installer will start
  right up
• Sometimes, a CD-ROM will not install from booting
  and you'll need a boot disk. The CD-ROM will
  usually contain a way on the disc on how to make
  a floppy boot disk.
• Once you've made this boot disk, you'll be able
  to boot up the CD-ROM

8
Partitioning

• Your hard disk is like a pie. You can divide it
  into sections. For example, if you had two
  partitions, popular operating systems would
  generally call them C and D. You can call them
  whatever you want
• Linux doesn't use them, though. Linux may call
  them /hda3 and /hda5 for example.
• You will also need another partition known as a
  'swap' partition. This 'swap' partition is just a
  way that Linux uses to get more memory so that
  you don't run out of it.

9
Partitioning

• The classic way of partitioning your hard disk is
  with a program called 'fdisk'. This is the
  dangerous way to do it. The re-partioning using
  this method will get rid of everything forever
• But installing Linux isn't dangerous. If you're
  fortunate enough to have a hard drive with more
  than one partition (the old C and D routine),
  then it may be just a question of moving some
  files around.
• If you didn't have two partitions already made,
  then there's a tool called FIPS that comes with
  major Linux versions. This will re-arrange your
  hard drive so you can install Linux. There are
  also other programs you can download that will do
  the same and help you move things around and make
  new partitions.

10
More partitioning

• Now that you have the CD in the computer and you
  have a place to put Linux, the installation will
  ask you to further repartition the hard drive.
• This is because Linux puts different pieces on
  different parts of a hard drive (in different
  partitions).
• There are generally four or five partitions that
  you will need for sure.
• These are the swap partition, root, home and usr

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More partitioning

• Let's take a 10 gigabyte hard drive as an
  example. First, you should see how much RAM you
  have. From this figure, you create what's known
  as a SWAP partition. This is simply a way that
  Linux uses to get an extra memory boost. Usually,
  your swap partition should be double your RAM
  memory. So if you've got 256 megabytes of RAM,
  the feel free to make a 500 megabyte swap
  partition.
• Then the partitioning ends up looking like this
• Partition Location Size
• swap /dev/hda2 500 mb
• / (boot) /dev/hda1 1.2 gb
• /usr /dev/hda3 3.5 gb
• /home /dev/hda4 5 gb

12
More Partitioning

• Assign partitions to look like this. You must
  indicate here that you want / to be the bootable
  partition. /usr will contain most of the programs
  that will run on your machine. /home will contain
  your personal files. This kind of a partition
  scheme may come in handy if you have problems
  with your hard disk. You may be able to save
  information if it's located in different
  partitions easier than if it were only one big
  partition.
• Before we actually assign the other partitions
  their places and functions, we need to initialize
  and activate a the swap partition.
• After, you should initialize the / partition -
  the one that will boot the Linux kernel.

13
Partitioning

• Different distributions will ask for different
  partitions as well that will serve different
  purposes.
• The best rule is to give enough space to the
  different parts for your type of system
• For example, if you will have many users on a
  system, you will want to give more space to the
  /home partition, because your users will all have
  space in the home directory
• If you want to have a lot of programs, give more
  space to the /usr partition
• Most of the time, the distribution will choose
  sizes for you and these sizes are generally
  pretty good

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The rest of installation

• At this point you should have your hard drive
  partitioned and these partitions assigned to what
  areas they'll be housing.
• Now, comes the point in the process to install
  the Linux kernel. You can choose additional parts
  to add to the kernel, known as modules, to better
  use your hardware. Unless you need something
  specific, the installation program will choose
  the correct ones you need
• Next, you'll have to choose a 'hostname' or name
  for your computer. Use whatever name you want for
  the computer. After, you should choose a 'domain'
  name. Even if your not running an Internet server
  and even if you don't have a network you should
  choose a name as if you had one. Normally if you
  were in fact a server providing Internet
  services, you would choose a name and append
  .com, .net etc on the end. Example yahoo.com,
  google.com

15
Making it bootable

• Now, as we're installing from a CD, you should
  choose 'CD-Rom' for the installation procedure.
  You should also choose the settings 'make system
  bootable'.
• Your hard disk is basically a piece of metal with
  a metal disk flying around in it at incredible
  speeds. It essentially does nothing unless you
  tell it to do. At this point, we're going to tell
  it to boot up the Linux operating system.
• If you have a dual-boot system, you can also tell
  it to ask you to choose from different operating
  systems at boot.
• These are programs called Boot Loaders. One good
  one is 'LILO'. Later, you can actually make
  alternative versions of the Linux kernel and have
  LILO boot them.

16
Adding packages

• Different distributions will have different
  orders for their installations. At this point,
  most will ask for what packages you want
  installed on the system
• Packages are just programs that will run on your
  computer. They could be web browsers, web
  servers, Gnome or KDE.
• Often there will be guidelines for what kind of
  computer you want, Server, Workstation or
  Desktop. Each will give you a different
  configuration for packages
• If you have a lot of harddrive space, you can
  install everything and not worry about what you
  might need in the future
• If you're short on space, you can choose the
  minimalist package. We'll go into what programs
  you'll need for what kind of computers later on.

17
Choose Passwords

• You'll be asked for a root password at some
  point.
• The root user, you'll remember, is the superuser,
  the most important user who can do anything they
  want.
• So you don't want anyone else to be able to guess
  the password or else they can do whatever they
  want to your computer.
• A good password will have numbers and letters and
  special characters (,.gtlt!_at_). People can
  also use password crackers and these will make a
  brute force attempt to guess your password, but
  if you use numbers, letters and special
  characters, it will be very hard to guess

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Other installation issues

• The rest of the installation is pretty simple,
  but sometimes things go wrong when the software
  tries to detect hardware.
• Most distributions will have a long list of
  hardware device drivers they use to get the
  operating system to talk to the hardware.
• Sometimes it doesn't have the right hardware or
  it can decide what hardware you actually have.
• In this case, your best bet is too choose
  manually what you have from a list. If it's not
  on the list, then choose the most generic form.
• For example, if you have a monitor but can't find
  it on the list, look for Generic VGA 800x600.
  Most likely it will work and then you can search
  online later to find the correct driver

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The end of installation

• Now you have installed Linux. Remove the CD and
  reboot the computer. When it starts up again
  you'll be able to choose which operating system
  (if you have more than one) and you'll see a
  login screen. That's where you type in the root
  username and password.
• What to do after that?
• That's what we'll be focusing on for the rest of
  the classes.

20
Installing new programs

• So you finished installing Linux, but what
  happens when you need to get a new program or you
  need to update an existing program?
• Installing programs on Linux is sometimes very
  easy and sometimes painfully difficult.
• The first objective is to find the program on the
  internet. The best bet is to search with
  google.com to find what you need.
• Other sites that also have a lot of Linux
  software are
• http//www.linux.org
• http//www.sourceforge.net
• http//rpmfind.net
• http//www.ibiblio.org

21
Installing new programs

• There are two ways to install a new program on
  your system.
• You can download the source code and compile it
• Or, you can download a binary package.
  Different distributions use different types of
  systems. Redhat and SuSE will use what is called
  an rpm file. This is like a program all bundled
  up into one file and then you just need to run a
  command and it will install on your system
• Of course sometimes things aren't that easy.

22
The easy way RPMs

• RPM stands for RPM package manager. It's a way to
  download, install, verify and update packages on
  a system.
• Each software package consists of an archive of
  files along with information about the package
  like its version, a description, and the like.
• When you go to get a RPM from a website (like
  http//www.rpmfind.net) you'll want to look for
  the one that most closely matches your system.
• For example, if you have RedHat 9.0 installed and
  you want a rpm for a package but can't find one
  made for RedHat 9.0, choose the one that says
  RedHat 8.0 or RedHat 7.2. This is because the rpm
  will put files in different places that it thinks
  the system follows.

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The easy way RPM

• Now that you've downloaded your rpm package for
  your system, time to install it
• For example, if the name of the package you
  downloaded is called mozilla.rpm, to install it,
  we'd type into the shell
• rpm -U mozilla.rpm
• The -U stands for upgrade, which is the safest
  way to do it. You can also try
• rpm -i mozilla.rpm
• This will install the program, but generally does
  not work as well as the -U

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Problems with RPMs

• Unfortunately, RPMs aren't always so easy.
• The thing about RPMs is that they might assume
  you have other files and programs already
  installed on your computer.
• So sometimes when you try to install, you'll see
  stuff like this
• root_at_usp root rpm -U bittorrent-3.2.1b
• error Failed dependencies
• python-base gt 2.2 is needed by bittorrent
• This means that you need the program called
  python-base (and a better version that 2.2)
  before you can install the program called
  bittorrent.
• So what can you do? Begin the search for other
  files

25
More RPMs

• Sometimes you'll be led on a wild chase to find
  all the packages. Because when you go for the
  package that is missing, sometimes that package
  will also need other programs. It can be a big
  headache.
• The other downside about RPMs is that they put
  files and programs in places where maybe you
  don't want them.
• You won't always know where they go, and they
  might overwrite files that you think are
  important.
• So there is another way, luckily for us.

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Installing from source

• So we don't RPMs, and a lot of the time we won't
  be able to find one, so the other option is to
  download the source code of the program and to
  compile the program ourselves. This is actually
  not as hard as it sounds
• So now you'll download the source code and it
  will usually be in one of 3 formats, .gz, .zip or
  .bz2
• These are all compression formats used to make
  the files smaller so it's easier to download.

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The first step Decompressing

• So the first step we need to do after downloading
  is to decompress the file.
• If it ends in .tar.gz this means it's gzipped
  and put together with tar. Tar is a program that
  puts directories and many files together into one
  file. Then gzip is a way to decompress files
• We can decompress in one small simple step
• tar zxvf kxine-0.4.tar.gz
• The 'z' says first decompress. The 'x' says to
  expand the tar file. The 'v' says to output any
  messages and the 'f' says use the file that
  you're going to type after

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Other Compressions

• If you get a file that ends in '.bz2' you'll use
  the bunzip2 program. Bunzip is a good
  compression, better than even gzip
• bunzip2 kxine-0.4.2.bz2
• The last format you will probably see is the
  '.zip' format. This is the compression used on
  most Windows machines. You can also use it with
  Linux
• unzip kxine-0.4.2.zip
• Now you'll have a folder with the source files
  and you'll be ready to compile

29
Installing from source

• After decompressing, you'll need to change into
  the new directory with the files. For example,
• cd kxine-0.4.2
• Now the best thing to do is to open the README or
  the INSTALL file. Usually there will be one or
  the other. These will tell you the exact steps to
  take to compile and install.
• Most programs today will follow a general
  guideline of steps that most other programs
  follow.
• With these steps, things are pretty easy.

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Compiling

• In all likelihood, the INSTALL or README file
  will tell you do to the following.
• root_at_usp root ./configure
• root_at_usp root make
• root_at_usp root make test
• root_at_usp root make install
• The configure says to run a little program that
  will check your system for everything it needs
  and where to find it. If configure runs and it's
  all good, then you can type make
• make is a program used to compile other programs.
  So now you will see a lot of output where the
  computer is compiling
• make test will make sure it compiled correctly
• make install will put the program in the right
  place

31
Installing from source

• When you install from source, there are
  potentially many more things that can go wrong.
  Sometimes the configure program will tell you
  what's wrong and how to fix it.
• If you get a compiler error though, it means that
  the program was not able to find everything it
  needed. In that case, it's best to give up and
  look for another program that will do the same
  thing.
• Unless you really need that program, dealing with
  compiler errors is more of a headache then it's
  worth

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Summary

• Installation with most Linux distributions is
  very easy these days. Using RedHat 9.0, it's very
  simple, just follow the steps, and you'll be on
  your way to using Linux in no time
• Installing programs is getting easier, but there
  still can be lots of problems if something on
  your system is missing or it's in a place that is
  not expected.
• It can be quite time consuming and difficult to
  get programs to compile and install when they
  don't work right away, but usually there are 3 or
  4 other programs that will do the same thing in
  Linux.