How Linux Works: What Every Superuser Should Know

by Brian Ward

How Linux Works describes the inside of the Linux system for systems administrators, whether they maintain an extensive network in the office or one Linux box at home. Some books try to give you copy-and-paste instructions for how to deal with every single system issue that may arise, but How Linux Works actually shows you how the Linux system functions so that you can come up with your own solutions. After a guided tour of filesystems, the boot sequence, system management basics, and networking, author Brian Ward delves into open-ended topics such as development tools, custom kernels, and buying hardware, all from an administrator's point of view. With a mixture of background theory and real-world examples, this book shows both "how" to administer Linux, and "why" each particular technique works, so that you will know how to make Linux work for you.

Genres: Computer Science, Programming, Technology, Computers, Technical, Reference, Nonfiction

368 pages, Paperback

First published May 1, 2004

Reviews

[Christopher · Rating 5 out of 5]

For making a book about Linux only ~340 pages long, it's hard to find one this complete and educational. Out of the dozens of books I've bought on Linux, this is the one I keep turning to over and over again.

True, with the more recent live-cd's and other gadgets made for the general public, you may not use some of the things written in this book (old utilities, &c) but it really has everything you should know to maintain and develop on these systems.

Especially if you're going to install Linux on some old'n'busted machines or some low-powered embedded systems that can't handle all the bloat of the name-brand SUSE/RedHat/Ubuntu shizzle, you'll find this book invaluable.

The author did a GREAT job on this. I couldn't come 1/10th as close as he did to perfection, and this is coming from a guy that keeps reading his book.

[Anton Petkov · Rating 5 out of 5]

I can say with confidence that this is one of the most useful books I have ever read as a beginner. I like the fact that the book covers so many topics and it gives you a very good jump start as a Linux user. I would recommend this book to everyone who wants an introduction to Linux at a beginner or intermediate level.

I bought the paperback copy of the second edition of How Linux Works and read it with pleasure while commuting. I read the book while attending the Operating Systems and Computer Networks courses in the university where I studied and practiced almost everything covered in the book.

Wish I had read this book earlier.

EDIT: I finished the Operating Systems course with the 2nd highest score from more than 100 people after finishing the book. And the next year I became a teaching assistant for this course and I started teaching GNU/Linux. I am doing it 2nd year in a row now. Of course, I read other sources too, but this book gave me the jump start. Thank you!

How far can this book take YOU?

[Tyler · Rating 3 out of 5]

I've been reading quite a few books on Linux recently, and this one has been the most comprehensive and technical. It was actually a bit of a challenge for me to get through, and I took a lot of notes.

The author does not always articulate himself as clearly as I would like, but it covered a lot of concepts relevant to the LPIC-1 exam (including the boot process, bash scripting, libraries, managing files, etc.) plus more, and did so in far greater depth than a lot of the other material I've been using.

I would recommend this book, but only to someone who is already somewhat familiar with Linux, programming, and computers.

[Jascha · Rating 4 out of 5]

Another great title published by No Starch Press. If you are a Linux power user, Brian definitely knows how to properly feed your desire to know more about what’s happening under the hood, without getting into the details of titles such as The Linux Programming Interface or Advanced Programming in the UNIX Environment. Easy to read and follow, it’s a long long talk about many of the topics that make Linux what it is today.

I don’t remember a single tech book published by No Starch Press that did not deliver. How Linux Works certainly does. It gives the reader a good understanding of many hot topics of the Linux internals without getting too technical. It’s like a long long talk with one of those friendly geek guys that has been tinkering the kernel forever.

Brian covers many different subject. Among them, I have absolutely enjoyed the chapter dedicated to the booting process. Here the author gives you both an overall and a specific vision of the whole process, from boot loaders to the different major init implementation (systemd, Upstart, and System V).

Another juicy chapter is that dedicated to networking and firewalls. Lots and lots of concepts to learn and notes to take.

The book ends with several chapters dedicated to developers. These cover some basic shell scripting and developing. Not my favorite part of the book. Mainly, there are other titles that cover those subject in depth (see above).

Overall, a very nice title for anyone interested in knowing how Linux works, without getting too technical.

Suggested readings:
Linux Shell Scripting Cookbook: a very similar title, but focused towards scripting and thus, a little more oriented to System Administrators, rather than Power Users.

As usual, you can find more reviews on my personal blog: http://books.lostinmalloc.com Feel free to pass by and share your thoughts!

[Matthias · Rating 4 out of 5]

This is overall an excellent book. I've been working with computers for 25 years and learned a fair bit from this book. It is in fact a great introduction to operating systems and computers in general, not just Linux. I think if someone ever asked me "how do computers work?" I would not hesitate to point them to this book to build a holistic picture.

However, despite how condensed the material is, the sheer breadth of content found in this book got a little out of hand in my opinion. It covers literally everything you could possibly think of and then some, from SCSCI and spinning drive internals over boot manager configuration, networking protocols, the X window system to at least honorable mentions of some popular programming languages and databases. Considering that all of this had to fit onto ~400 pages, it's an incredible feat, but due to the lack of depth in some of these sections, I wonder what the intended audience was for those, as for both layman and expert alike some sections were too shallow to be useful.

But for any section that lacked depth, there were 5 others that did not, so there is still a wealth of information here that is useful to pretty much anyone with an interest in computers and operating systems.

Recommended!

[Tuấn Anh Nguyễn · Rating 5 out of 5]

Even as a rather experienced user, I find this book very useful. Beginners would get a lot out of it.

[Michael Koltsov · Rating 4 out of 5]

This book doesn't claim to cover all Linux features, but definitely it covers some of the most important ones.

It's easy to read, though it encompasses lots of useful information. I wish my first Linux book was like that.

The only complaint I had with it was that though its second edition has been recently issued and it wasn't strictly specified on which Linux distribution should I run some of the commands from the book I wasn't able to try some of them due to that there were no such packages in the APT repository for reference Ubuntu Docker image I've been using.

This is definitely not a book I would recommend to a SysOps, unless he needs to quickly brush-up his skills. But if you're a "superuser", that's the book you should definitely read to know what's "inode" any why top&vmstat&iotop might be much more powerful than you've thought.

My score 4/5

[Diego Garcia · Rating 5 out of 5]

Excelente overview sobre o linux passando desde o kernel (incluindo boot load) ate chegar no Desktop X

[briz]

More of a reference book than a "I'll just sit down and read it cover to cover". But I need this info. GIVE ME THIS INFO. Happy with it.

[Ray · Rating 5 out of 5]

Just so happened that my local library had this book so I picked it up.

It was pretty dang good. My only complaint really is that sometimes it felt like a topic was mentioned without really explaining it enough (like how a connection stays open) but at the same time I recognize the limits of the book not being able to go into every detail.

Overall, for someone who has used linux for years I still learned a lot and quite enjoyed reading it. It is a good mix of how to and history of why things got to be how they are.

I wasn't taking extensive notes since much of it was review but I did jot down a few things from each chapter.


Ch1
Most processes run in user mode
Ones that don't are in kernel mode and have unrestricted access to the hardware
Even root user is not operating in kernel mode

Ch2
Shell variables are not passed to programs you call. Only env variables are.
Use export for env variables
Use this=that for shell variables

In the PS command time is how much time actually using CPU happened. Different from wall-clock time of his long since a process started

You can use kill -STOP pid to basically pause a process for resuming later

Ch 3
Device files are one way of interacting with devices on Linux. There are 4 different types: block, character, pipe, socket
VM disks may have a different ptevis like /dev/xvd
SCSI is a lot to understand
Writing to an optical drive is not part of the kernel because it's not critical to any system


Ch 4
Btrfs is positioned to replace ext4
LVM logical volume manager makes it much easier to work with storage

Ch 5
Linux kernel booting and EFI and MBR and all that fun stuff

Ch 6
Learned much about systemd and how user space starts

Ch 7
Learned about the at command for scheduling things in the future
Learned a bit about Pam the plugable authentication module

Ch 8
lsof let's you see which files a process has opened
strace and ltrace are powerful debugging tools I should learn
Threads are similar to processes but multiple threads in a process can share the same resources.
You can change the nice value of a process to deprioritize it so it doesn't bog down other processes. The higher the nice value the nicer the process is being to other processes and therefore the less priority it gets


Ch 9
Wow there's a lot that goes into networking. Now I know a little bit more about TCP, UDP, NAT, ARP, and more

Ch 10
Nice explanation of more user level networking

Ch 11
Mktmp is an awesome command for making temp files

Ch 12
File sharing has so many options still and no clear winner

Ch 13
To change what you see when you open the terminal change the prompt
Aliases are not great because of the confusion from them and it's not easy to see where they are configured

Ch 14
Transition from xorg to Wayland
Dbus is desktop bus to let programs talk to each other or learn about events such as USB stick being added
Printing is kinda complicated


Ch 15
Reaffirmed I don't want to work with C.
Compilers are complicated

Ch 16
Wow compiling big software projects seems like a serious amount of work

Ch 17
There are two types of hypervisors: one where there is a host and a guest and one where the host is the hypervisor itself
Containers aren't as complicated as I thought

[Dainius Prakapavičius · Rating 4 out of 5]

Lots of information in this well-condensed book. The author does good job to explain basics of various complex topics without delving into infinity of details, and by providing valuable references instead.

[Miguel · Rating 5 out of 5]

Absolutely the best Linux book I've read.

A good mix of practical and theoretical content really lives up to the title "What every superuser should know". I've been using Linux for quite some time but there are a few things I never quite understood but the book really helped me learn it and manipulate it like an expert.

I will say I recommend, anyone reading have at least an intermediate level understanding of Linux. If you're a beginner I would say try another book and come back to this once you've cut your teeth on a few compiler problems.

Highly recommended!

[Daniel Q · Rating 3 out of 5]

Good book, but not as good or complete as the blurb suggests. It does cover a lot of ground, but most of the time it is superficial. A few times it looked like it drifted away from the subject when it was getting really interesting. The "real-world examples" are few and not very helpful.

[Majakub · Rating 4 out of 5]

Good overview of linux world with not too deep insights into os details.

[Enzo Altamiranda · Rating 4 out of 5]

Excellent book to understand the fundamentals of linux and operative systems. Full of examples and interesting facts that could help even a seasoned user to brush up on some fundamental concepts.

[Nick · Rating 3 out of 5]

If you are a systems administrator, or an aspiring one, I'd highly recommend this book. In fact, this book was recommended to me by my Systems Administrator professor. In terms of reading as a normal home Linux user, which I am, I'd still definitely recommend this book, though there are quite a few parts that you can safely skip over without losing sleep. I'd consider myself somewhere around lower-intermediate in terms of Linux knowledge, but I found that some of the first few chapters required knowledge of concepts that not many beginners would be expected to know, so I wish he would have explained some of those underlying ones better.

I believe it would have been more appropriate to start off explaining the network topics, which seemed the most basic chapter, followed by going from the ground up from how the kernel boots and eventually ascending to the user space, etc. As a home user this book has a lot of useful information, but again I feel it's mainly directed towards a systems administrator or at least an aspiring one.

[Dale · Rating 4 out of 5]

After a brief chapter on the most basic of GNU/Linux command-line tools, Ward dives right into Linux internals, starting with a lengthy walk-through of the boot process. followed by in-depth coverage of devices, file systems, and networking.

The final third of the book covers applications, the desktop, and development tools.

I can see this being useful as a thorough introduction to Linux for someone who plans to spend a lot of time doing Linux-y things; and also as a refresher/tutorial/quasi-reference if you want to do something like setup a samba server or figure out how to get a printer connected.

Overall good clear linear exposition.

[Vỹ Hồng · Rating 5 out of 5]

I have been using Linux for years, in my university days and my day-to-day work. This book is very educational and quite comprehensive for its length. It helps bridged many gaps in my knowledge on topics such as device management, boot-loading process, network configurations, and resource management. The author has a knack for explaining complex concepts in simple words. Though, I also find the contrary in certain cases. But, since I have the liberty to skip over those, I did.

I'd recommend this book if your work involves managing Linux servers, or that you are curious to learn more about the operating system.

[Farsan Rashid · Rating 4 out of 5]

I have not read the book from cover to cover but the most significant chapters(IMO). Definately recommend to anyone looking for their first Unix book as it is short (350 pages), to the point and easy to read.

[Eric Thomas · Rating 4 out of 5]

This is a very informative book that any software engineer or person who runs Linux should read. It filled in a lot of the gaps for me and introduced me to a lot of concepts I was not familiar with. This book provided a wide breadth of topic with sources that go deeper if you want to learn more

[Prabhu Pant · Rating 5 out of 5]

Quite decent and informative! This is a kind of a book that should be pursued with ease.

[Hildey · Rating 4 out of 5]

Good, but strays too far from Linux itself at some points.

[AJ · Rating 5 out of 5]

I absolutely love this book.

[William Schram · Rating 4 out of 5]

"How Linux Works" does what it describes. Brian Ward takes us on a whirlwind tour of the Linux Operating System. There are numerous flavors of Linux available, so Ward tells you which one he is talking about in the text. Ward would prefer that you had a copy of Linux available to work on while you read this book, but I did not have that privilege. I do most of my reading at work and do not have access to a computer there.

The book does not go into the history of Linux. Ward makes some recommendations if you are interested in that aspect of the Linux OS.

Modern Operating Systems are complicated. Multiple pieces are working in sync. Thankfully, Ward doesn't go into too much detail. I didn't want to read a brick anyway.

[Chibimagic · Rating 3 out of 5]

This book really showed how patchy my knowledge of Linux is. But it also explained things very poorly. Some chapters covered stuff I was already familiar with, so it was way too elementary. Other chapters covered stuff I didn't know at all, and I don't really feel like I left with a better understanding of those concepts. And the chapter on compiling from source started going into debugging someone else's code??

This book would really benefit from some reference charts/diagrams/lists. For example, a list of common Linux commands grouped by functional area (working with directories, text processing, etc).

Anyway, you should read this book in front of a Linux terminal so you can follow along and execute commands to get a better understanding for yourself.

[Jack Graves · Rating 2 out of 5]

I was surprisingly underwhelmed by this book. Yes, it explained what each command does and when you should use it, but it explained almost of none of the fundamentals of how these commands work. This book in my reading was akin to the Linux man docs. I was really hoping to learn about how Linux works at a fundamental level in this book, because that is what actually teaches people how to use the operating system best. Unfortunately, this just taught the surface level. But if you are just looking for a quick easy guide to various commands and concepts and don’t enjoy reading the Linux man docs, this book would work well for you.

[Anton Antonov · Rating 5 out of 5]

Whether you're a enthusiast, student, employed software developer or sys admin - this book will do you good. As a software developer, I loved the shell scripting and networking chapters. I learnt a lot in a well organized way and know what else to read, since through the chapters, you'll find a lot of paragraphs where the author recommends books that will help you learn more about the topic(s).

Full review: http://blog.syndbg.com/review-how-lin...

[Patrick Coakley · Rating 3 out of 5]

I think this is a decent book for getting to know a lot about Linux in a short amount of time, but I felt it was very much "a mile wide and an inch deep" approach. Much of the content is skippable for experienced users, but it's an easy read and think it's worth a recommendation for newer Linux users out there who want to know a bit more without getting mired in the details. Based on the description I expected more, but I enjoyed it well enough.

[Tassos · Rating 3 out of 5]

A good book, neither too advanced nor too basic. However, even thought I'm not a super advanced Linux user myself, there are not so many things that this book had to offer.

One thing I certainly missed was more complete examples of commands and more hands on tasks for the reader.

[Eugene Popovych · Rating 2 out of 5]

More a bunch of manuals and howtos than a detailed book about Linux internals. Could be interesting as a reference or investigation guide for different Linux components for somebody. Not for me though.