Topic 101: System Architecture Flashcards
What is the purpose of the /sys/ directory?
provides a filesystem-like view of information and configuration settings that the kernel provides, much like /proc.
What is the purpose of the /proc/ directory?
holds all the details about your Linux system, including its kernel, processes, and configuration parameters.
What is the purpose of the /dev/ directory?
The dev directory is the location of special, or device files.
What does the modprobe command do?
To add or remove modules on Linux.
What will the lsmod command output show?
The lsmod command is used to display the status of modules in the Linux kernel.
What will the lspci command output show?
lspci is a command on Unix-like operating systems that prints, or lists, detailed information about all PCI buses and devices in the system.
What will the lsusb command output show?
The lsusb command in Linux is used to display the information about USB buses and the devices connected to them. The properties displayed are speed, BUS, class, type details, etc.
What is the purpose of “dmesg”?
dmesg command also called as “driver message” or “display message” is used to examine the kernel ring buffer and print the message buffer of kernel. The output of this command contains the messages produced by the device drivers.
When the computer boots up, there are lot of messages(log) generated during the system start-up.
So you can read all these messages by using dmesg command. The contents of kernel ring buffer are also stored in /var/log/dmesg file.
Describe the role of the journalctl command.
journalctl command in Linux is used to view systemd, kernel, and journal logs.
What does BIOS stand for?
Basic Input/Output System
What is the role of BIOS?
It is used by the CPU to perform start-up procedures when the computer is turned on.
Its two major procedures are determining what peripheral devices (keyboard, mouse, disk drives, printers, video cards, etc.) are available and loading the operating system (OS) into main memory.
What does UEFI stand for and what is it’s role in the Linux OS?
Unified Extensible Firmware Interface.
UEFI does the same job as a BIOS, but with one basic difference: it stores all data about initialization and startup in an .efi file, instead of storing it on the firmware. This ESP partition also contains the bootloader.
What is a bootloader?
A boot loader, also called a boot manager, is a small program that places the operating system (OS) of a computer into memory. When a computer is powered-up or restarted, the basic input/output system (BIOS) performs some initial tests, and then transfers control to the Master Boot Record (MBR) where the boot loader resides.
Examples: GRUB (GRand Unified Bootloader), LILO (LInux LOader)
Describe a kernel.
The Linux® kernel is the main component of a Linux operating system (OS) and is the core interface between a computer’s hardware and its processes. It communicates between the 2, managing resources as efficiently as possible.
What is initramfs?
Initramfs is used as the first root filesystem that your machine has access to. It is used for mounting the real rootfs which has all your data. The initramfs carries the modules needed for mounting your rootfs.
