This first part in a series looks at how you can use repositories to make it easy to install, upgrade, and maintain your Linux software.

1. Installing Software Part 1
Kevin B. O'Brien
Washtenaw Linux Users Group
http://www.lugwash.org

2. Audience
● This is intended for the new user just getting
started on Linux
● I will assume that most new users are coming
over from Windows
● I will not assume much knowledge of Linux
2

3. Distributions
● I will focus on three representative
distributions:
– Ubuntu
– OpenSUSE
– Fedora
● These are likely starter distros for new users
● Most other distros are related in some way or
use similar technology
3

4. Dependencies 1
● This is the first key concept for installing
software
● Linux is built on a modular model – instead of
one large monolithic installation file, each
package installs only the specific file for that
package, and everything else is in other files
that are shared among all software packages
● These other files are called “dependencies”
4

5. Dependencies 2
● Years ago, dependencies caused a lot of
problems
● Today, this is usually not a problem (though
you can run into an occasional snag)
● One analogy is that dependencies work in a
similar way to *.dll files in Windows, which
are also shared among applications
5

6. Dependencies 3
● The main problem is when two different
programs each need a different version
● In Windows, it often means the last one
installed over-writes whatever was there
previously
● In Linux, it will note the conflict, and refuse to
do the installation
6

7. Dependencies 4
● In Windows, there is no way to know which
application wanted a particular *.dll, nor can
you keep track of these problems
● In Linux, most package managers today will
keep a record of this information, and warn you
if you try to change a shared library (this is kept
in a database)
● Package managers may even insist on removing
an application if you force the removal of a key 7
file needed by that application

8. Packages
● Packages are the name used in Linux for the
installation files for software
● They contain the code for the application
● They also contain information about any other
files (dependencies) required for the software to
work properly
8

9. Package Managers 1
● Most of the time, you can do what you need
using a Package Manager
● This is a software program that keeps track of
what is installed on your system (in a database)
● It also looks at the dependencies, and if
possible will download and install any other
files needed for your application to work
properly
9

10. Package Managers 2
Ian Murdock has commented that package
management is "the single biggest advancement
Linux has brought to the industry", that it blurs the
boundaries between operating system and
applications, and that it makes it "easier to push
new innovations [...] into the marketplace and [...]
evolve the OS".
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11. Package Managers 3
● Package Managers can also catch conflicts, and
give you an error message rather than overwrite
a file that you need for something else
● Among the major package managers are:
– Dpkg for Debian
– RPM for Fedora
– Libzypp for OpenSUSE
11

12. Package Managers 4
● Package Managers can be handled entirely on
the command line
● There are also GUI interfaces that may be
easier for a new user:
– Synaptic for Ubuntu
– YAST for OpenSUSE
– PackageKit for Fedora
● Others may also be available if you look
12

13. Repositories 1
● These are online collections of downloadable
software
● They are designed to work with a Package
Manager
● There are large repositories set up by the distro
vendor that have all of the basic OS files, and
sometimes a distro-specific version of thrid-
party applications
13

14. Repositories 2
● There are also repositories set up by third party
vendors to supply their own applications
● These are often divided into different sections
for distro “families”
● Distro “families” come about when a person or
group decides to create a “spin-off” distro
based on a previously developed one
14

15. Distro Families
● Debian is the source for Xandros, Knoppix, and
Ubuntu. In turn Ubuntu gave rise to MEPIS and
Linux Mint
● Red Hat gave rise to Fedora, Mandriva, and
TurboLinux
● This matters when you are looking at packages
and repositories, because the one you need is
often based on what “family” you are part of
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16. Repositories 3
● For example, Ubuntu has become so popular
that it often has its own repositories, but it is
usually fine to add a generic Debian repository
● Similarly, a Fedora or Mandriva user will
generally be fine with any Red Hat or RPM
repository
16

17. System Diagram
R e p o s it o r ie s
P a c k a g e
M a n a g e r P a c k a g e M a n a g e r
D a t a b a s e
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18. Repositories 4
● You should have the repositories for your distro
already in the database when you install the OS
● But you can add more
● Look for repositories designed for your distro if
possible, or at least for your family
18

19. GUI for Package Management
● These all work in pretty similar ways
● They allow you to add or remove repositories
● You can search for software by name, or
browse by categories
● Unless it is a very specialized type of
application (and often even then) you will find
software to do just about anything you want to
do if you have the right repositories
19

20. Synaptic 1
● This is the default GUI for package
management in Ubuntu, and is commonly used
● Go to System → Administration → Synaptic
Package Manager to start it
● You will need to supply your password to run
this since installing software is a system
administration task
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21. Synaptic 2
21

22. Synaptic 3
● Note you can browse by selecting a category on
the left, or you can search by selecting “All”
and entering a search on the upper right
● You can reload the database for the most up-to-
date information from the repositories by
clicking the “Reload” button
● You can look at packages by whether or not
they are installed by clicking the “Status”
button on the lower left 22

23. Synaptic 4
● You can see which repository each package
comes from by clicking the “Origin” button on
the lower left
● You can view by various filters as well
23

24. Synaptic 5
● To manage your repositories, go to Settings →
Repositories
24

25. Synaptic 6
● The two tabs you are most interested in are the
first two, Ubuntu Software and Third-Party
Software, but we'll look at all 5
● On the first tab, note that Ubuntu gives you
several options
– Main is the repository for Ubuntu-supported
packages. These are all open, non-
proprietary, and non-controversial.
– Universe is similar, but maintained by the
community, not by Canonical employees. 25

26. Synaptic 7
● Non-free software
– You can uncheck these repositories if you do
not want any non-free software on your
system
– This would mean no binary drivers for
hardware, no proprietary codecs, no playing
of DVDs, etc.
– But if you want to do these things, you can
enable these repositories as well
– Proprietary Drivers is for hardware drivers and 26
is in Restricted, and codecs and DVD playing
are in Multiverse

27. Synaptic 8
● Third-Party Software lets you add repositories
from other software providers
● Examples: Google, Miro, Sun, VirtualBox
● You need to get the repository address from the
Web site, generally
27

28. Synaptic 9
28

29. Synaptic 10
● For example, go to
http://www.virtualbox.org/wiki/Linux_Downloads
● You will this line, which you can copy
deb
http://download.virtualbox.org/virtualbox/debian
jaunty non-free
● The “deb” at the beginning identifies this as a
“Debian” style repository. At the end, you can see
that it is for Ubuntu Jaunty, and is not a “free”
package 29

30. Synaptic 11
● In the Third-Party Software screen, click “Add”
and copy the entire line, beginning with “deb”,
and ending with “non-free”
● If at a later time you need to stop using a
repository for some reason, you can either
remove it, or just remove the check mark to
disable it temporarily
● You can also Edit each entry (e.g. change
“intrepid” to “jaunty”) 30

31. Synaptic 12
● The third tab lets you fine-tune what you will
pull down from Ubuntu repositories
● You can have it check for updates, and notify
you when they are available. You can even
have security updates automatically installed if
you wish.
● If you don't like living dangerously, this is a
good place to not check for pre-release and
unsupported updates  31

32. Synaptic 13
32

33. Synaptic 14
● On tab 4 you can check and add signing keys
for your repositories. This is how you can be
sure you are getting the files from the right
source.
● On the last tab, you can help Ubuntu find which
packages re most popular by agreeing to submit
statistics. This might be useful.
33

34. PackageKit 1
● This is the Fedora Package Manager
● It is very similar to Synaptic, which is not
surprising since they do similar things
34

35. PackageKit 2
35

36. PackageKit 3
● Again, you can search for a specific package by
putting the name in the upper left box and
clicking “Find”, or you can browse by category
● You can refresh the listings of packages from
your repositories by going to System →
Refresh Package Lists
● You can work with your repositories by going
to System → Software sources
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37. PackageKit 4
37

38. PackageKit 5
● Obviously, the repository system is not as
developed in Fedora
● But it will probably be developed more with
time
● For instance, in Fedora 11, there is now
provision for installing “firmware” or drivers,
for hardware
● However, there is also a philosophical
difference in how Fedora views Third-Party 38
Repositories

39. PackageKit 6
● See http://www.packagekit.org/pk-faq.html
● “Allowing to easily add third party repositories and
install third party software without a certification
infrastructure is like opening the gates to hell. Most
user just don't have got the technical understanding
to handle this well.” _ Sebastian Heinlein
● There is a way, though: installing the repo-
release.rpm package which also adds the GPG keys
39

40. PackageKit 7
● To install the RPM packages means going to
the command line
● Installing from the command line will be
covered in the next installment of this series on
installing software
● We will definitely cover installing RPM files in
that installment
40

41. YAST 1
● YAST is the SUSE tool for managing packages
● YAST does a lot more. It is the general
administration tool in SUSE.
● To begin installing software with YAST, go the
SUSE button in the lower left, then to
Applications → Configuration → Install
Software
41

42. YAST 2
42

43. YAST 3
● This looks a little different from Synaptic and
PackageKit, but does the same kinds of things
● The “Filters” box is important here. If you set it
to “Search”, you can search for specific
packages
● If you set it to Package Groups, you can browse
for packages by category
● To see your repositories, go to Configuration
→ Repositories 43

44. YAST 4
● Again, only the official repositories are here by
default
● But YAST is a little less prickly than
PackageKit about adding Third-Party
repositories
● There is a good list at
http://en.opensuse.org/Additional_YaST_Packa
ge_Repositories
44

45. YAST 5
● To add a Third-Party Repository, click the
“Add” button on the Repository screen
● On the next screen, you will have “Specify
URL” and “Download repository description
files” selected by default
● Click “Next”, and you can enter the URL of the
repository
45

46. YAST 6
46

47. YAST 7
● Click “Next” and the repository will be added
and information downloaded
● Then you will be back at the Repository screen,
but with a new Repository now listed
47

48. YAST 8
48

49. Software Updates
● Package Managers will check the repositories at
intervals (usually once a day) for updates to your
software
● This can be security or bug fixes (as with Windows
Update) but this is even better
– It covers all of your packages, not just the OS
– It can include updates to new features and new
versions
● If you do not use Package Managers and
Repositories you don't get this 49

50. Final Thoughts
● Using these Package Managers and
Repositories is the easiest way to access a
wealth of software
● When you can use them you probably should
● Using Package Managers and Repositories lets
you get automatic updates and fixes. If you
install in other ways, you don't get this benefit.
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