Note: This is not a tutorial on how to install Linux on your system, there are plenty of tutorials available online. I have mentioned the tutorial I used at the end of this blog. Here, I have discussed some very basic terminology I came across while installing Linux, and i figured how little I knew about them, so I researched a bit and then blogged it!
If you are new to Linux, which I still am, and you are considering installing Linux, then you would probably have heard terms like BIOS, Disk Partition, Swap Space, Distros, Bootable pen-drives, ISO files and these could be overwhelming at first, but they will make a lot more sense once we understand some of their functionality and their use.
Since most of us use Windows OS for our system (which is generally pre-installed by the manufacturer), we have no experience with installing an OS and quite often don’t want to mess with what has come pre-installed, and this can get in the way of learning. I didn’t install Ubuntu until 4th Semester (I should have done it before) and when I did, I feared losing Windows so much that, I configured dual-booting on my system. I hardly used Ubuntu the whole semester, because I always had to option to “boot” into Windows. So finally, I decided to make Ubuntu as my only OS!
Now getting to the terminologies we often come across:
Linux is a computer operating system (like Windows or OS X), which is assembled under the model of free and open-source software. Basically it means that source code for Linux is available to general public for use and also for modifications if necessary. So any user can modify the code to suit their needs.
So Why Linux? Personally, I feel there is a lot of learning involved while using Linux. Some times we cannot use the user-interface and need to work with command line, which I believe is a good thing, because when we use command line we understand the steps involved in the background and hence get a basic understanding of how the system works. Also, since we are new to the operating system we tend to Google a lot and in the process learn some new stuff and tricks!
Now, since we are discussing Linux, the next question could be are Linux and Ubuntu the same?
Linux and Ubuntu are not the same, Ubuntu is basically a flavor of Linux or we can say Linux forms the core of Ubuntu. Since Linux source code may be used, modified and distributed by anyone, there are many available distributions of Linux, Ubuntu is one among them! Ubuntu is a distro!
Short for distribution, distro is a term used to describe a specific distribution of Linux that is built from the common Linux operating system and includes additional applications - Source webopedia</span>
Some famous distros are Ubuntu, Fedora, Arch-Linux, etc. Ubuntu is the among the most famous distros for beginner’s while Arch-Linux is for advanced users.
According to Wikipedia:
ISO images are expected to contain the binary image of an optical media file system, including the data in its files in binary format, copied exactly as they were stored on the disc! The .iso file extension is the one most commonly used for this type of disc images. Any single-track CD-ROM, DVD or Blu-ray disc can be archived in ISO format as a true digital copy of the original. Unlike a physical optical disc, an image can be transferred over any data link or removable storage medium.
Thus, ISO image provides with easy an alternative, to share over the network which optical disc’s does not! Why we discussed ISO images is because when we download a distro, it is available in a .iso format and we need to use that file to create a Bootable USB and then install that distro!
The ISO image file is a popular image of the CD/DVD discs, an ISO file can include all the content on the disc, by burning these ISO files to a USB flash disk we can create a bootable USB and then install the OS. We could have also done the same using an optical disk, but then its easier and more convenient to use a USB. So, What does booting from a USB mean?
USB boot is the process of using a USB storage device to boot or start a computer’s operating system. It enables computer hardware to use a USB storage stick to get all essential system booting information and files rather than the standard/native hard disk or the CD drive. - Source techopedia
So, How exactly does USB booting work? Now, there is a region in storage devices (USB, Hard Disk, etc. ) called boot sector, that contains machine code to be loaded on to the RAM by the computer system’s built in firmware (like BIOS). The purpose of a boot sector is to allow the boot process of a computer to load a program (generally an operating system) stored on the same storage device. Thus, when we use an application to create a bootable pen drive, this is what happens in the background. The application formats the USB, installing the boot loader in boot record of the device and hence making the USB device bootable.
BIOS (basic input/output system) is the program a personal computer’s microprocessor uses to get the computer system started after you turn it on. BIOS is an integral part of your computer and comes with it when you bring it home. When you turn on your computer, the microprocessor passes control to the BIOS program. When BIOS boots up (starts up) your computer, it first determines whether all of the attachments are in place and operational and then it loads the operating system (or key parts of it) into your computer’s random access memory (RAM) from your hard disk or diskette drive.
So basically, BIOS is a built-in software that determines what a computer can do without accessing programs from a disk. Hence, to boot from the USB, we enter the BIOS mode and then choose the option to boot from USB.
You may have installed multiple operating systems on your computer, and in such cases you need to decide which operating system to boot from and that is where GRUB comes in.
GNU GRUB is a boot loader package, which provides a user the choice to boot one of multiple operating systems installed on a computer or select a specific kernel configuration available on a particular operating system’s partitions.
Disk partitioning is used to mean the partitioning or division of certain kinds of secondary storage via the creation of multiple partitions. Partitions are logical containers which are usually used to house file-systems, where operating systems, applications, and data are installed on. - Source Wikipedia
So, Partitioning helps in creating segments with-in the secondary storage. In case you are planning on installing multiple OS, you will need to partition the disk accordingly. An operating system has its own set of file-systems and by creating different partitions we can house different OS’s on different partitions.
We may also use partitions to differentiate between the OS files and the storage location. For example, if in future you are plan to install a different OS or may be re-install the same OS, then it would make sense to have different partitions for your OS and data, so that when you install your OS, you don’t lose your data.
Also, we create a partition for the Swap Space, which we will discuss in a while. A common configuration for Linux desktop systems is to use two partitions: one holding a file system mounted on “/” (the root directory) and a swap partition.
A file-system is the methods and data structures that an operating system uses to keep track of files on a disk or partition; that is, the way the files are organized on the disk. - Source tldp
So basically, an operating system has its own set of file-systems it supports and the partitions are used to house these file-systems.
Swap space in Linux is used when the amount of physical memory (RAM) is full. If the system needs more memory resources and the RAM is full, inactive pages in memory are moved to the swap space. While swap space can help machines with a small amount of RAM, it should not be considered a replacement for more RAM. Swap space is located on hard drives, which have a slower access time than physical memory. Swap space can be a dedicated swap partition (recommended), a swap file, or a combination of swap partitions and swap files. Swap should equal 2x physical RAM for up to 2 GB of physical RAM, and then an additional 1x physical RAM for any amount above 2 GB, but never less than 32 MB.
Now that we know some of the terminologies which we come across while installing Linux, I hope it would make much more sense! :) In case you wish to use Ubuntu as your only OS (which I highly recommend), you should follow the instructions from this tutorial.