Linux Made Simple

Every time I come to write an introduction to one of these guides, I seem to relate a story of how I’ve ruined something by being unprepared. This guide is no different. My first experience with Linux was one of desperation: I really had to try it, being an unabashed computer nerd, and when I finally got my hands on an early copy of Mandrake Linux – in a box, on a real CD-ROM! – I set to installing it without thinking. I didn’t need that software or those documents, it seems. I also didn’t need a working computer, clearly, as Linux wasn’t particularly friendly when it came to compatibility at the time. Things have changed. Modern Linux distributions tend to work first time with whatever hardware you have. Every…

Made Simple books are designed to get you up and running quickly with a new piece of hardware or software. We won’t bombard you with jargon or gloss over basic principles, but we will… ✓ Explain everything in plain-English so you can tackle your new device or software with confidence and really get to know how to use it ✓ Break instructions down into easy-to-follow steps so you won’t be left scratching your head over what to do next ✓ Help you discover exciting new things to do and try – exploring new technology should be fun and our guides are designed to make the learning journey as enjoyable as possible for you ✓ Teach you new skills you can take with you through your life and apply at home…

The word ‘Linux’ is one of the most used in this book, but what does it mean? It means different things to different people, from the purist who considers it to be the kernel, to the GNU advocate who sees it as a part of GNU/Linux and the new user who thinks it is another name for Ubuntu. In truth, Linux is all of these, depending on your point of view. Strictly speaking, the term Linux used alone refers to the kernel of the operating system, while GNU/Linux is the whole operating system, comprising the Linux kernel and GNU tools – either would be useless without the other (or one of its alternatives). If you then add a collection of application software, along with some tools to manage the whole…

An operating system can be defined as the software needed to enable the applications to run on the hardware – as such, it consists of several interleaved layers. At the heart we have the kernel, which interacts directly with the hardware through its drivers and allows other software to use that hardware. On top of that, we have various layers that handle things such as input devices, networking, sound and video. Normally, you don’t need to know anything about this. It can be helpful to know some of it when things go wrong, but even then it is not essential, especially if you can find someone to fix the computer for you. But if you are reading this book, there is a good chance that you are interested in what…

The kernel is the beating heart of the system, but what is it? The kernel is the software interface to the computer’s hardware. It communicates with the CPU, memory and other devices on behalf of any software running on the computer. As such, it is the lowest-level component in the software stack, and the most important. If the kernel has a problem, every piece of software running on the computer shares in that problem. The Linux kernel is a monolithic kernel – all the main OS services run in the kernel. The alternative is a microkernel, where most of the work is done by external processes, with the kernel doing little more than co-ordinating. While a pure monolithic kernel worked well in the early days, when users compiled a kernel…

Most distros go straight to a splash screen when booting, so we don’t see what is happening. In fact, there’s a lot going on both before the splash screen appears and then hidden by the screen. The BIOS starts up first, in the motherboard’s hardware. It looks for a boot device and loads code from there. In the case of a hard drive using the traditional DOS partition system, this is contained in the Master Boot Record (MBR) of the drive – just 512 bytes of storage. 64 bytes are used to hold the partition table for the drive (which is why only four primary partitions are available), leaving all of 446 bytes for the bootloader code, usually Grub. 446 bytes doesn’t give room for much in the way of…