A Look Inside Linux series
A series of short topics on how Linux works and how to make it work the way you want it to, which I present during the weekly sessions of the Linux User Net. The target audience is Hams who are new to Linux and want to know more about it, as well as experienced Linux users who can learn more about their chosen operating system. These are my notes for the presentations. (Russ, KC7MM)
Unfortunately, it's hard to buy a computer that has Linux pre-installed. So, to get your own Linux box, you likely will have to install the OS yourself.
Happily, that's not a big deal. Installing a modern Linux distribution generally is a straightforward process, requiring only some general computer knowledge.
The installation procedure depends on the system you want to have.
The Web is awash with HOWTO articles that detail the installation of particular distros, and I won't repeat them here. Rather, I'll look at the general installation process in order to get you started in the right direction.
Today I'll cover the two types of system you're likely to use: desktop and server.
Embedded Linux systems are a very specialized niche area that we might explore at another time.
The installation procedure can vary depending on the hardware on which you want to install it. ( See here for definitions and more information.)
The PC platform has fewer variants and thus is the simplest to use. Its hardware also is most likely to be supported by the Linux kernel and the community.
SBCs are trickier, owing to all the possible permutations. Hardware and software support can vary greatly, so care in selection is required. The Raspberry Pi, for example, is not necessarily the best SBC for any particular job, but its vast community support makes it highly versatile and easy to work with.
Every Linux distribution has its own installation method. That usually comes in the form of an installation program. These programs require varying degrees of technical knowledge on the part of the person running the installation.
Let's presume you have selected your hardware and a Linux distribution you want to run on it. The next step is to download the software for your distro.
The standard way of distributing Linux is to create a bootable disc image (ISO file) and make it available for download. The ISO contains all the software necessary for the target computer to boot and run Linux. From there, the user can either run applications or install the disto to a disc drive, depending on the distro selected.
So, go to your distro's download site, select the ISO for your computer's architecture (e.g., AMD64) and, if the distro has multiple variants, the variant that you want to use.
Having downloaded the image, the next step is to put it on a medium from which the target computer can boot it. The options are:
Since this is a system image, the normal file copy operation won't work. Instead, the ISO must be placed on the boot medium exactly as it is structured in the image file, bit by bit. There are special tools for this for Linux, Windows, and OSX. (My Linux Mint system comes with a “USB Image Writer” utility that I use for this.) The Linux command line dd utility also can be used.
Once you have prepared the boot medium, the next step is to insert it into the appropriate input device on the target system (optical drive or USB or SD card slot) and turn on the power.
The computer should detect the ISO and boot from it. (If the system already has an OS installed, you might have to use the system setup utility to change the boot order so the new Linux image will be detected first.)
Once the boot process is complete, the user has a working Linux system. In most cases, that system will be one of these:
Let's look at each one in turn.
The purpose here is to install the distro on a fixed drive (HDD, SSD). At minimum, the user is required to select a drive or partition for the install, plus language, keyboard layout, time zone, and to create a default user. Once configured, the program does the rest. When completed, removed the boot medium and reboot the computer.
This is the method of choice for most server installations.
Some installers, such as Debian's, give the user a choice of system type to be installed, (e.g., server or desktop) and possibly specific applications or application types as well.
Desktop-only distributions generally boot into a live desktop session, allowing the user to run it without making a disc drive installation. Log in as the default user (check the distro's documentation for this), and you're good to go. This is a good way to test the distro's compatibility with the machine's hardware.
Most such distros also offer to install themselves on a disc drive. (This often appears as a desktop icon.) Choosing that option launches an installation program, as above.
Many single board computers have no fixed drives, instead running their OS off of a removable boot medium, such as an SD card. With these, the installation is complete once it's booted up, although some configuration is likely to be required.
We've seen that, although the task of installing Linux on a computer can have many variations in detail, there is a general procedure that is common to all installations:
There is a Step Zero: get the specific details of installing any Linux distribution by checking its documentation and following the installation instructions you find there.