101 System Architecture KT

Question 1

101.1 Determine and Configure Hardware Settings

Answer 1

The following is a partial list of the used files, terms and utilities:

/sys/
/proc/
/dev/
modprobe
lsmod
lspci
lsusb

Question 2

/sys/

Answer 2

Directory that stores structured device data migrated by sysfs.

Question 3

/proc/

Answer 3

Directory that stores unstructured info about devices and processes.

Question 4

/dev/

Answer 4

Directory that stores device files.

Question 5

modprobe

Answer 5

Command: Adds or Removes a module from the Linux kernel.

Question 6

lsmod

Answer 6

Command: Displays the kernel modules loaded.

Question 7

lspci

Answer 7

Command: Displays information about PCI bus and devices.

Question 8

lsusb

Answer 8

Command: Displays the USB information and devices.

Question 9

101.2 Boot the System

Answer 9

The following is a partial list of the used files, terms and utilities:

dmesg
journalctl
BIOS
UEFI
bootloader
kernel
initramfs
init
SysVinit
systemd

Question 10

dmesg

Answer 10

Command: Displays all messages from the kernel ring buffer.

Question 11

journalctl

Answer 11

Command: used to query the contents of the systemd journal logs.

Question 12

BIOS

Answer 12

Basic Input Output System - connects firmware to an operating system.

Question 13

UEFI

Answer 13

Unified Extensible Firmware Interface - connects firmware to an operating system.

Question 14

bootloader

Answer 14

Code that runs before any operating system. It usually contains several ways to boot the OS Kernel.

Question 15

kernel

Answer 15

A computer program that makes up the core of the computer. It interfaces between the hardware and software.

Question 16

initramfs

Answer 16

Prepares the system to load the root file system from RAM.

Question 17

init

Answer 17

init (initialization) is the first process that is started during the booting of the system. It is the parent of all processes and continues running till the system is shutdown.

Question 18

SysVinit

Answer 18

SysVinit is a Linux initialization system and service manager that starts processes in a serialized manner(one by one).

Question 19

systemd

Answer 19

systemd is a Linux initialization system and service manager that includes features like parallel initialization, on-demand starting of daemons, mount and automount point maintenance, snapshot support, and processes tracking using Linux control groups. systemd provides a logging daemon and other tools and utilities to help with common system administration tasks.

Question 20

101.3 Change Run Levels / Boot Targets and Shutdown or Reboot System

Answer 20

The following is a partial list of the used files, terms and utilities:

/etc/inittab
shutdown
init
/etc/init.d/
telinit
systemd
systemctl
/etc/systemd/
/usr/lib/systemd/
wall

Question 21

/etc/inittab

Answer 21

Configuration file used by the System V (SysV) initialization system. It defines for the init process:
The defaul runlevel.
What processes to start, monitor, and restart.
What actions to take when the system enters a new runlevel.

Question 22

shutdown

Answer 22

Command: Brings the system down in a secure way.

shutdown [OPTIONS] [TIME] [MESSAGE]

Question 23

init

Answer 23

init (initialization) is the first process that is started during the booting of the system. It is the parent of all processes and continues running till the system is shutdown.

Question 24

/etc/init.d/

Answer 24

/init.d directory contains start/stop scripts for services on the Linux system.

Question 25

telinit

Answer 25

Command: telinit may be used to change the system runlevel.

telinit [OPTION]… RUNLEVEL

Question 26

systemd

Answer 26

systemd is a Linux initialization system and service manager that includes features like parallel initialization, on-demand starting of daemons, mount and automount point maintenance, snapshot support, and processes tracking using Linux control groups. systemd provides a logging daemon and other tools and utilities to help with common system administration tasks.

Question 27

systemctl

Answer 27

Command: systemctl is a controlling interface and inspection tool for the widely-adopted init system and service manager systemd.

systemctl [OPTIONS…] COMMAND [NAME…]

Question 28

/etc/systemd/

Answer 28

Directory where admin configurations are stored for systemd units.

Question 29

/usr/lib/systemd/

Answer 29

Directory where vendor/distibution supplied files and configurations are stored for systemd units.

Question 30

wall

Answer 30

Command: (Write to all) Used to display contents of a file or standard output to all logged in users.

wall [file]