Review of The Debian System: Concepts and Techniques

Aric Campling -- 24 February 2006 (C) -- Page 3

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Article Index Introduction Executive Summary About Debian GNU-Linux Is The Debian System: Concepts and Techniques for You? A Book for Reading and for Reference What's on the Included Debian CD Contents of The Debian System: Concepts and Techniques Debian's package management tools About the review author Resources Books

Figure 1. A somewhat simplified, logical cross-section of a Linux-based computer system. Please see Anatomy of a Linux Distribution in our article SCO Clears Linux Kernel but Implicates Red Hat and SuSE. for the details, an explanation, and a bigger figure.

About the review author Aric S. Campling is a nursing informatics specialist at an academic hospital in the Boston area. He has several years' experience working with enterprise healthcare information systems as a systems analyst. Aric has been a GNU-Linux user for more than eight years, starting with Red Hat Linux in 1995 and converting to Debian GNU-Linux in 2003. He is mostly self-taught in the ways of computers, information systems, and Linux. Aric approaches his writing from the viewpoints of computer user and system administrator -- focusing on how to make the most efficient use of the computing tools at hand. His current computer runs Debian GNU-Linux 3.1r1 with a customized Linux kernel. It is running various servers, such as SSH for secure shell access, Apache2 web server in both public and secure modes, SquirrelMail, webmail portal, and the Asterisk PBX for Voice over IP. Running these applications and services gives Aric both system administrator experience and user experience. Aric's academic research interests include technology and nursing practice and topics such as information technology, robotics, and cyborg theory. He currently has a paper, pending review, with a refereed, academic journal about nursing information systems and project management methodologies. He co-authored a chapter in Technological Competency as Caring in Nursing: A Model for Practice, (Locsin, R. C. (ed.), Sigma Theta Tau International, Indianapolis, Indiana. 2004) entitled Techno Sapiens and Post-Humans: Nursing, Caring, and Technology. Additionally, Aric is lead author for a chapter about robotics in nursing care, included in a book on nursing and technology, which is currently under editorial review and due to be published in 2006. Aric also is a graphic artist, responsible for the artwork and some of the writing at the only-mildly-popular web comic, H.O.S.E.R.S.: The Comic Strip. He has a number of other comic projects currently in the design phase. Aric also is the administrator and designer of the Web Comics Map Project, an interactive atlas that shows where in the world participating web-comic creators reside.

Pristine Kernel Pristine means "Unspoiled, in its original state" (Wiktionary). A pristine kernel is clean, uncluttered, and unmarred by user modifications or by modifications made by a package maintainer who is required to cater to a multitude of potential system configurations. The only pristine kernel is the one downloaded from kernel.org or a kernel .org mirror. Once I configure a pristine kernel, it's no longer pristine. It is uniquely mine.

Debian's package management tools

And now, the centerpiece of The Debian System: Concepts and Techniques: Central to the Debian GNU-Linux distribution is a set of core utilities that comprise the Debian package management system. Years before other distributions could do it, Debian's package management tools provided a sane, automatic, and massively intelligent system for package installation, configuration, management, and removal.

Today, many other distributions now have similar software management capacities, such as Mandriva's urpmi tool, which is based on Debian's APT. A Linux distribution is not just about how its programs are packed, shipped, installed and removed. Nevertheless, Debian's APT concept might play a major part in the choice a user makes when selecting which Linux distribution to use.

Chapter 5, The Debian package management system encompasses almost a full quarter of the book. It goes into great detail about the Debian package management system and most of its tools, including third-party utilities that extend core functionality or make use of the core utilities to ease specific tasks. The chapter begins with an exploration of:

(1) what good package management should do,

(2) the different types of Debian packages,

(3) what they're for, and

(4) how they're used.

DEB is the package format name given to Debian packages (all Debian package file names end with .deb). The DEB naming convention and package format are explained in Chapter 5.

One by one, Debian's package management utilities are described in Chapter 5. Information is provided on how best to use these tools efficiently through command line use, configuration files, and environment variables.

The core tools are dpkg and APT. They are not only tools, but also each describes a family of related tools. Both have a menu-based front-end (dselect and aptitude), both have a family of child tools (such as dpkg-reconfigure, apt-get, and apt-cache), and graphical front-ends (such as synaptic for APT).

Martin F. Krafft also briefly compares the various package management functionalities across distributions. He makes the comparisons by lining up similar functions between dpkg (Debian PacKaGe manager) and rpm (Red-Hat Package Management), and amongst APT (Advanced Package Tool), yum (YellowDog Updater, Modified), up2date (RpmFind.net package tool), and urpmi (Mandriva's rpm wrapper).

After Krafft has explained the package management tools, he delves into the concept of package relationships and how the various tools utilize this information to keep a sane system running smoothly. Central to this chapter is an explanation of the Debian policy, which among other things describes why installing one package might mean you must install another package first.

Sometimes, a Debian user wants to install a package from another distribution entirely. For example, this reviewer, a Debian user, is using an OpenOffice 2.0 package that originally was packaged as an RPM. Using alien, the author was able to convert the RPMs to DEBs and install them. Alien, as well as a few other software management tools, also is described in Chapter 5.

In Chapter 5 Martin F. Krafft details a set of additional Debian software management tools that aid the user or administrator in maintaining a clean, streamlined system. These tools are designed to utilize specific functionality of the dpkg or APT tools, such as:

• finding broken dependencies,
• finding files that are not owned by any packages,
• finding packages that have no dependency restrictions,
• and so forth.

The end goal is to remove unnecessary packages, and make sure the necessary ones are present.

Finally in Chapter 5, Debian's kernel package structure is examined. Here, Martin F. Krafft discusses the method users can employ to fetch a Debian-packed kernel source in order to modify it to their specific needs.

Chapter 6, Debian system administration explores the Debian approach to system administration. Concepts such as user/group policy, file-system structure, system backups, kernel modules and module loading, system logging, network administration, and integrated management tools are discussed.

Chapter 7, Security of the Debian system details the Debian security strategy, and tools for ensuring and verifying the integrity of the packages users install on their system. Debian GNU-Linux prides itself on balancing stability and security in its stable releases. Debian has an entire team dedicated to security. This team monitors packages and ensures the quality of packages in the stable release. This chapter shows some tools the reader can use to ensure their system is as current and as secure as possible.

Chapter Eight, Advanced concepts delves into the more advanced concepts of Debian GNU-Linux. The primary interest here is the description of using the kernel-package tools to create Debianized kernels from pristine kernel sources from kernel.org or one of its mirrors. This reviewer uses this method exclusively on his own Debian system.

(Please see the Pristine Kernel note in the right side-bar, above.)

Another concept discussed in Chapter 8 is mixing Debian releases. For instance, a user may use primarily stable but want to install a package from testing. This and other concepts regarding advanced APT configuration are presented here.

Finally in Chapter 8, alternatives to Debian installation are presented. Using a bootstrap loader, a user can use an existing Debian system to install a new Debian system into a sandbox system. (A virtual Debian running inside a different root directory, and therefore sequestered from the primary system while sharing its kernel.)

With slight modifications, the user can then convert the sandbox system into a fully-bootable, standalone system. This reviewer has used this process many time to install Debian GNU-Linux onto a PC using a Knoppix Live-CD instead of a Debian install disc. This process, using Knoppix to install Debian, is also detailed in Chapter 8 quite accurately.

If this process isn't quite what you need, Martin Krafft further expands on Debian installer concepts in Chapter 8. He details methods for customizing the Debian Installer and for creating fully automatic installations (FAIs), installations that are done without any user input.

FAI is a flexible installation management method. It can be used, for example, to handle installations across an enterprise organization.

Chapter 9, Creating Debian packages describes in some detail the structure of a Debian package. It describes how users can create their own Debian packages.

This is important. For example, it is important if a user makes custom modifications to source code for a specific package but wants the package to be recognized by dpkg and APT, It also is important if a user creates or finds a new program and wants to share it with other Debian users by packaging it and submitting it to the Debian project.

Chapter 10 Documentation and resources describes various resources in print and on-line where Debian users can get more information. Also listed in Chapter 10 are unofficial resources, which are presented as a list of annotated websites. Discussion forums, mailing lists, and Internet Relay Chat venues also are listed. Finally in Chapter 10, an explanation of the Debian Bug Tracking System is given -- and how it can be used to learn to communicate with the Debian developers and maintainers.

Appendix A lists information about some of the Custom Debian Distributions and many of the Debian derivative distributions (such as Knoppix).

Appendix B helps the user decide when Debian is the right choice (and when it's not).

Appendix C has miscellaneous information, such as GPG keys and info on how to configure a multi-boot system (for example, Linux and Windows on the same computer).

Appendix D is the Debian Linux Manifesto.

Appendix E is the Debian Social Contract.

Appendix F is the Debian Free Software Guidelines.

Resources

Part 3. Advanced Cheating

Give the Gift of Knoppix Linux and a Book for Less Than $30 -- Knoppix for Dummies

Santa's 2005 Picks for Linux and Windows Computer Gifts

A Glimpse of SUSE Linux 10.0 and Other Things Brewing at Novell

A Glimpse of OpenOffice 2.0 -- Now Available for Free Public Downloading

Is It Deja Deja Novell All Over Again, Again? -- Ximian/GNOME v SUSE/KDE at Novell

Good Sound, Easy Listening, and Good Value Lexar LDP-200 Digital Music Player and SD Card Reader for Linux, Mac, and Windows

The Many Faces of Linux

In Pursuit of Good Desktop Linux:

KDE, KMail, and Konqueror Articles

Mandrake Linux 10.1 Official - 2.6 Linux kernel

Gaël Duval Tells Why Mandrake Linux Is Better Than MS Windows

Microsoft PR Does Not Refute Mandrake Linux Better Than Windows

Mandrake Linux 9.0, Desktop Magic You Can Use: A First Look

Linux Networking for Windows and Desktop People -- Mandrake 9.1 and LinNeighborhood

Gaël Duval and Mike Angelo Discuss Mandrake Business Products and Finances

MandrakeSoft Adds MandrakeClustering to Its Business and Enterprise Products Lineup

Gaël Duval and Mike Angelo Discuss The HP-Mandrake Computer

HP to Ship Desktop PCs with Mandrake 9.1 Linux Pre-Installed - Good News for Mandrake Linux and Fans

Gaël Duval and Mike Angelo Discuss the New Mandrake AMD64 OS

Mandrake Linux Corporate Server 2.1 for AMD Opteron

Mandrake Linux Shows Profit -- End to Bankruptcy Near

Conectiva, Mandrake, and SuSE Say No SCO in Their Code

SCO-Caldera v IBM: Conectiva's Gordon Ho Responds to SCO-Caldera's Linux-Related Allegations

Mozilla 1.3b Browser-Suite Released

Mozilla 1.0 updated!

Netscape 7.02 Browser-Suite Released

Mozilla and Netscape JavaScript Bugs Compromise Privacy and Security

Is Netscape Losing the Browser Wars?

Linux for Microsoft Windows Users: #4-- Getting Started Using the Windows-Like Desktop for Linux

Linux for Microsoft Windows Users: #2 - Getting Started with The Linux MS Windows-Like Desktop

Linux for Microsoft Windows Users: Introduction & Overview