Introduction to Linux
Linux is a great concept. It is a wonderful kernel and has wonderful userland
utilities making it a perfect operating system. But for most people, it is quite
new and too exciting to just dive in. This part tries to cover Linux: what is
it, how does it work, what can you expect etc.
What is Linux?
What is Linux exactly? How does this all fit in "Free Software"? What is a
distribution and why would you care? How is Linux developed? What can you expect
from it? All that is covered in this chapter.
Users and the Linux file system
Linux is built upon the UNIX knowledge and concepts. This means it is fairly
robust and uses a very logical approach to files, users and such. But for most
people, this logical approach is just what seems the most illogical since they
are not used to it. In this chapter, we try to inform those users about how
Linux sees a multi-user environment and what the Linux file system is structured
like.
Freedom, support and finances
The most powerful asset of the Linux operating system is the freedom it gives
you. But many folks are afraid that this freedom comes with a price: no support,
no company backing up Linux. This is all FUD (Fear, Uncertainty, Doubt) and well
explained in this chapter.
Staying up to date
With the decentralised development model that Linux uses, keeping a system up to
date might seem like a huge effort. Indeed, it is, but it is covered by the
various distributions (such as Gentoo). However, because of the openness that
the development model imposes, users have conflicting feelings about stability
and the differences between all version models. This chapter explains what all
the differences between version models are.
Making a choice
Now that most non-technical stuff is covered, it is time for you to make
choices. Will you use Linux? What distribution? What graphical environment? What
mail client? In this chapter we discuss the various differences between
major distributions and explain that, once you have picked a distribution, all
other choices are reversible.
Finding information
You have a lot of resources at your disposal, but you need to know where to look
for them. In this chapter we provide you a quick overview on the available
resources, how to use them for your queries and what you can do to contribute to
them.
So far so good
Now that the introduction to Linux has ended, we will talk about the next few
parts and the syntax we use throughout this document.
Installing Gentoo
So you decided to install Gentoo. That's great, so how to continue? Installing
Gentoo is a breeze, but not a soft one. You need to have a fair knowledge of the
Linux environment if you want to get it right from the first time. In this part,
we discuss how to install Gentoo using the available Gentoo media.
Versions, media and installation concerns
Gentoo provides installation media, with specific versions, for specific
architectures, for specific installation methods. This chapter informs you how
to pick the right media for your system.
Starting from a minimal environment
The start of every Gentoo installation process begins with a minimal Linux
environment, allowing you to extract a basic Gentoo environment on your disk.
Regardless of what minimal environment you are in, you need to know a few basic
things about the system. This chapter covers the use of important tools.
Preparing the network
When you are known to the minimal environment, it is time to get the network up
and running. We will inform you how a network is set up, what TCP/IP is and how
to deal with networking on Linux, including wireless networks.
Putting the minimal environment in place
In this chapter we prepare your disk(s) to store the Gentoo Linux environment.
We will cover a few additional storage concepts (LVM2, RAID) but the real use of
these technologies is postponed for later. Next, we store a minimal Gentoo
environment on your disks.
Building the system
Once the minimal environment was available, we took the dive and chrooted in it.
Now, we'll set up the basic configuration directives, build the Gentoo
system until it is bootstrapped and has the core system packages available.
Building the Linux kernel
The core of any Linux Operating System is the kernel. Configuring a kernel might
seem like a difficult task, but once you get to know how it works, it hardly is
a challenge anymore. In this chapter we will discuss how to configure and build
your kernel, either automatically using genkernel, or manually with the kernel
configuration dialog.
Configuring the boot process
The next step is to configure the boot process. The boot process covers the boot
loader tool, which loads the Linux kernel in memory, and the init process which
governs all the applications and processes that should start on a Linux system.
Configuring the system
Most of the system's configuration is stored inside /etc. In this almost final
chapter we describe what you should configure prior to rebooting (such as the
file system table, networking stuff, user accounts, ...). It is important to
read this entire chapter completely.
Finishing off
Now that everything is (hopefully) configured correctly, we reboot in the Gentoo
Linux Operating System to discover that we have a nice running minimal
environment. Now, where to go from here? You obviously can't work immediately
since nothing is installed yet...
Gentoo Linux for the desktop user
Most Gentoo users have a Gentoo-powered desktop system, yet are often unaware of
the massive tools and helpful features that Linux offers to increase their
desktop experience. In this part you'll find pointers to various tips and
tricks, but also best practices for desktop users.
Graphical Linux
Linux is not an operating system where command-line utilities must be used. Once
the system is installed, any user should be able to use it without any knowledge
of command-line utilities. Indeed, this is perfectly possible, but requires some
configuration. This chapter gives an introduction to popular graphical
environments and provides pointers to its configuration.
Plug and play
Your laptop detects an open wireless network and authenticates itself
immediately. You plug in your USB key which gets mounted immediately so you can
download the latest Gentoo release on it. While you are at it, your calendar
synchronises with your friends while your laptop tries to consume as little
power as possible because it is working on batteries. No, this is no utopia...
Software collaboration
Open standards allow for easy integration of different software tools. However,
the race for the best open standard hasn't been won, so various tools only work
with one standard while other tools use a different one. This chapter gives a
quick overview of the various collaboration-related standards and the
applications (or libraries which they use) that make use of them.
Gentoo Linux for enterprise environments
Enterprises require more than just a stable Operating System. Depending on their
requirements, a system should be high-available, have a high throughput, connect
with legacy systems, have a low maintenance cost, requires zero manual
configuration steps, etc. This part will attempt to discuss various interesting
topics that might help you get more out of Gentoo Linux.
Software RAID
If you need a very low-cost system but still want redundancy, using software
RAID is a minimal requirement. In this chapter we will describe how to use
software RAID within Gentoo Linux.
Logical Volume Management
With LVM, storage concerns can be tackled easily since your files are located on
top of a specific layer, able to hide the complexity of storage from the file
system. Learn how to store files across various file systems, moving data
without the need to put the system in a frozen state, take live backups without
having your data touched while you are busy, ... and all that using LVM2.
Backup systems
You don't want to lose your files, but eventually you will. Having backups at
hand is a prerequisite for good system householding, but is also often
overlooked or deemed less important. This chapter will cover a few basics on
backups and proposes a few solutions that will help you keep your data safe.
Print server
High quality printing is a requirement for every office. Linux makes a fine
print server, capable of interacting with all possible applications and
operating systems.
System Administration
Once your system is set up, your next concern is to decide how to administer the
system. Some people have made system administration their full-time job. We'll
try to keep the administration to a minimum without losing flexibility.
Software management
Gentoo's Portage is a powerful software management tool with lots of features.
Not only can you easily install and remove software, rebuild tools when they are
affected by changes or update your system entirely, it also supports prebuilt
packages and different repositories.
Log files
Not many resources talk about log files. Most documents assume that log files
are mentioned by the application documentation, yet many applications just
inform you what information you can find in the logs and that isn't sufficient
for a good log management policy. Log rotation, event filtering, summary
creation, ... are all aspects that this chapter covers.
Centralised system management
When you administer more than one system, it might be beneficial to set up and
maintain your environment from a single location. You can use SSH to log on to
other systems, but more advanced tools exist that offer a wide variety of
features.
Performance tuning
No system is equal, so many systems have one or more performance bottlenecks due
to general settings that aren't as optimal for their systems as they are for
others. You can increase your systems performance on many areas as long as you
understand why they are bottlenecks and what sacrifices you need to make to
increase the throughput.
Input/output performance
Storage performance. If there is one device in your system that has the highest
importance but one of the lowest access times, it is your storage. Disks aren't
fast, network storage isn't much better and memory disks are generally too small
to contain your entire system. So what can you do to increase the IO
performance?
Network performance
If you are on a 28.8 kbps network, you'll always find that it is slow. Many
people still think their network is slow while they're using a 1 Gbps network.
By identifying the bottlenecks in your network and designing a good topology,
you can increase the performance of your network to a good level.
Rendering performance
A gamers wet dream: screens and graphical cards that render 3D images so
detailed and so fast that it seems that you're looking through a window. Of
course, this isn't achievable yet, but it is possible to tune the 3D performance
of your card. Of course, we'll take a look at 2D rendering as well.
Software profiling
Programmers don't always write the most performant code; perhaps because they
rely on the compiler to enhance the machine code or because they want to write
clean and maintainable code, setting their priorities elsewhere. Using profiling
tools, you can find out where in the software the performance bottlenecks may
lie.
User-observed performance
Lately, developers have come to the conclusion that even the fastest solution
can lose against a less performant system - at least if a human being is to
observe and judge. Many interesting projects have emerged where design
patterns and guidelines are discussed that try to embrace the users thoughts on
speed and performance.
Appendix: architecture specific information
Not all aspects of a Gentoo Linux system are similar on all architectures. Some
small differences come up during and after the installation. This part will
cover all architecture-specific information, nicely divided in separate chapters
for each architecture.
The x86 Architecture
The x86 architecture covers all 32-bit Intel and Intel-clones, such as the
various AMD processors (the K-series and Athlon/Duron), VIA and Cyrix. The CPU
types range from the old (but functional) i386 to the latest Intel Pentium IV
and AMD Athlons.