Chapter 3_Linux Basics and System Start

Question 1

What is the Linux Boot Process?

Answer 1

The Procedure for Initializing the System.

Question 2

What does the Boot Process Consist of?

Answer 2

Everything that happens from when the computer power is first switched on until it is fully operational.

Question 3

What are the steps of the boot process?

Answer 3

Power On
Boot
Master Boot (MBR) - First sector of the Hard Disk
Boot Loader (GRUB)
Kernel (Linux OS)
Initial Ram Disk (Initramfs Image)
/sbin/init (parent process)
Comand Shelf using Getty
X Window System (Graphical User Interface)

Question 4

What is the First Step of the Boot Process?

Answer 4

BIOS (Basic Input/Output System) intializes the Hardware and tests the main hardware - called POST

Question 5

What are some hardware that turns on during the BIOS Stage?

Answer 5

Keyboard, screen

Question 6

What does POST mean?

Answer 6

Power on Self Test

Question 7

Where is the BIOS system stored?

Answer 7

On a Rom Chip on the Motherboard

Question 8

What Happens after the initial BIOS system starts?

Answer 8

The OS takes over

Question 9

What happens when the POST is completed?

Answer 9

the system control passes from the bios to the boot loader

Question 10

Where is the Boot Loader Stored?

Answer 10

on one of the hard disks in the system, either in the Boot Sector or the EFI partition

Question 11

What systems is the Boot Loader stored on the Boot Sector?

Answer 11

Traditiona BIOS/MBR systems

Question 12

What systems on the EFI partition?

Answer 12

EFI/UEFI systems

Question 13

What does EFI stand for?

Answer 13

Extensible Firmware Interface

Question 14

What are common Boot Loaders for Linux?

Answer 14

GRUB (Grand Unified Boot Loader)
ISOLINUX (Boots removable media)
DAS U-Boot (boots embedded devices)

Question 15

What is the boot loader responsible for?

Answer 15

Loading the Kernel Image and
the initial RAM disk or FILESYSTEM into memory

Question 16

How many stages does the Boot Loader have?

Answer 16

2

Question 17

What is the First stage for a BIOS/MBR system?

Answer 17

the boot loader resides at the first sector of the hard disk - also known as the MASTER BOOT RECORD (MBR)

Question 18

What does MBR stand for?

Answer 18

Master Boot Loader

Question 19

What is the size of the MBR

Answer 19

512 Bytes

Question 20

What does the Boot Loader Examine?

Answer 20

The Partition Table and finds a bootable partition

Question 21

What happens when it finds a bootable partition?

Answer 21

it searches for the secondary loader (GRUB) and loads it into Ram

Question 22

What does GRUB stand for?

Answer 22

GRand Unified Bootloader

Question 23

What is the Second Stage?

Answer 23

Residing under /boot a splash screen is displayed asking us to choose an OS to boot

Question 24

What happens after the BootLoader chooses the OS?

Answer 24

loads the Kernel of the OS into RAM and passes control to the Kernel.

Question 25

Typically, what is the first job of the kernal?

Answer 25

Kernel;s are almost always compressed, so its first job, is to uncompress

Question 26

Typically, what happens when the kernel uncompresses?

Answer 26

it will check and analyze the system hardware and the device drivers built into the kernel

Question 27

What is the First Boot Loader Stage in an EFi SYStem?

Answer 27

Firmware reads its Boot Manager data to determine which UEFI application is to be launched.

Question 28

What is the step after the BootLoader chooses the OS?

Answer 28

The initiramfs contains the necessary prgrams and binary files that perform the actions to mount the proper root filesystem

Question 29

What does initiramfs mean?

Answer 29

Initial Ram Filesystem

Question 30

What does UDEV mean?

Answer 30

User Device

Question 31

What is the UDEV responsible for?

Answer 31

figuring out which devices are present, locating the device drivers they need to operate properly, and loads them!

Question 32

What happens after the root filesystem is found?

Answer 32

The system checks for errors and is mounted.

Question 33

What does the mount system instruct?

Answer 33

the operating system that a filesystem is ready for use, and finds the MOUNT POINT

Question 34

What happens if the mount is successful?

Answer 34

The initi file is cleared from the ram and the init program on thye root filesystem is executed

Question 35

what is the root filesystem?

Answer 35

/sbin/init

Question 36

What does INIT stand for?

Answer 36

handles the mounting and povoting of the fiunal real root system files.

Question 37

What are the initiramfs associated with?

Answer 37

Programs and Binary Files

Question 38

What are the programs and binary files associated with?

Answer 38

mounting proper root system providing kernal functionality locating devices locatingf and loading drivers checking for error in root filesystem

Question 39

What does MBR stand for?

Answer 39

Master Boot Record

Question 40

What does BIOS stand for?

Answer 40

Basic Input/Output System

Question 41

What is the default command shell?

Answer 41

Bash

Question 42

What start up software is used by most new distributions?

Answer 42

SystemD

Question 43

Why systemd?

Answer 43

Because, it can boot using aggresive parallel feautures, and not as sequential steps

Question 44

What is a partition?

Answer 44

physcially contiguous section of a disk

Question 45

/bin/

Answer 45

Essential user interface commands

Question 46

/boot/

Answer 46

static files of the boot loader

Question 47

/dev/

Answer 47

device files

Question 48

/etc/

Answer 48

host specific system configutation

Question 49

/home/

Answer 49

user home directories

Question 50

/lib/

Answer 50

essential shared libraries and kernel modules

Question 51

/media/

Answer 51

mount point for removable media

Question 52

/mnt/

Answer 52

mount point for temporary mounted filesystems

Question 53

/opt/

Answer 53

add on application software packages

Question 54

/sbin/

Answer 54

system binaries

Question 55

/srv/

Answer 55

data services provdied by the system

Question 56

/tmp/

Answer 56

Temporary files

Question 57

/usr/

Answer 57

multi user ultilites and applications

Question 58

/var/

Answer 58

variable files

Question 59

/root/

Answer 59

home directory for the root user

Question 60

/proc/

Answer 60

virtual filesytem documenbting kernal and process status of text files