LFS101x Flashcards
When was Linux’ inception?
1991
The world’s largest and most pervasive open source software project in history
Linux
What does the Linux Foundation do?
Partners with the world’s leading developers and companies to solve the hardest technology problems and accelerate open technology development and commercial adoption
Who is the creator of Linux?
Linus Torvalds as a student in Helsinki, Finland, in 1991
The three major families of Linux distributions?
- ) Red Hat (including CentOS, Fedora, Oracle Linux)
- ) SUSE (including openSUSE)
- ) Debian (including Ubuntu and Linux Mint)
Which distribution is used as a testing platform for future RHEL releases?
Fedora
The most popular Linux distribution in enterprise environments?
RHEL (Red Hat Enterprise Linux)
The basic version of what distribution is also virtually identical to RHEL?
CentOS
Which distribution provides by far the largest and most complete software repository to its users of any Linux distribution?
Debian
Which distribution is a pure open source community project? (Not owned by any corporation)
Debian
What is a LTS version of a distribution?
Long term support
This distribution is widely used for cloud deployments
Unbuntu
The umbrella organization for many critical open source projects that power corporations, spanning all industry sectors
The Linux Foundation
The original operating system Linux was developed for?
Intel x86-based personal computers
Linux borrows heavily from which well-established operating system?
UNIX
The core of the operating system
The Linux Kernel
What does a full Linux distribution consist of?
The kernel plus a number of other software tools for file-related operations, user management, and software package management
Why might a Linux distribution use an older version of the kernel?
It’s extremely stable
The procedure for initializing the system
The Linux boot process
This consists of everything from when the power is first switched on until the user interface is fully operational
Steps in the boot process
- Power On
- BIOS
- Master Boot Record (MBR)
- Boot Loader (e.g. GRUB)
- Kernel
- Initial RAM disk (initramfs)
- /sbin/init
- Command Shell Using Getty
- X-Windows System (GUI)
What does BIOS stand for?
Basic Input/Output System
Where is the BIOS software is stored?
On a Read-Only Memory (ROM) chip on the motherboard
What happens when the computer is powered on?
POST (Power On Self Test)
What happens during POST (Power On Self Test)?
The BIOS initializes the hardware, including the screen and keyboard, and tests the main memory
Once the POST is completed what happens?
The system control passes from the BIOS to the boot loader (GRUB)
Where is the boot loader is usually stored?
The boot sector (for traditional BIOS/MBR systems)
The EFI partition (for more recent (Unified) Extensible Firmware Interface or EFI/UEFI systems)
Where is information on date, time, and the most important peripherals loaded from?
CMOS - A battery-powered memory store which allows the system to keep track of the date and time even when it is powered off
The most common boot loaders?
GRUB (for GRand Unified Boot loader)
ISOLINUX (for booting from removable media)
DAS U-Boot (for booting on embedded devices/appliances)
What is the boot loader responsible for loading?
The kernel image and the initial RAM disk or filesystem
This contains some critical files and device drivers needed to start the system
For systems using the BIOS/MBR method where does the boot loader reside?
The first sector of the hard disk, also known as the Master Boot Record (MBR)
What is the size of the Master Boot Record (MBR)?
512 bytes
What are the two distinct stages of the boot loader? (BIOS/MBR)
- ) The boot loader examines the partition table and finds a bootable partition
- ) Then it searches for the second stage boot loader (GRUB), and loads it into RAM
What are the two distinct stages of the boot loader? (EFI/UEFI)
- ) UEFI firmware reads its Boot Manager data to determine which UEFI application is to be launched and from which disk and partition the EFI partition can be found
- ) The firmware then launches the UEFI application (GRUB) as defined in the boot entry in the firmware’s boot manager
Where does the second stage boot loader reside?
/boot
What happens when the second stage boot loader is run?
- ) A splash screen is displayed, which allows us to choose which operating system (OS) to boot
- ) The boot loader loads the kernel of the selected operating system into RAM and passes control to it
- ) The kernel uncompresses itself
- ) The kernel checks and analyzes the system hardware and initializes any hardware device drivers built into the kernel
What contains programs and binary files that perform all actions needed to mount the proper root filesystem?
The initramfs filesystem image
This program instructs the operating system that a filesystem is ready for use
mount
This handles the mounting and pivoting over to the final real root filesystem
init
What starts a number of text-mode login prompts?
init
How can the terminals which run the command shells be accessed?
Using the ALT key plus a function key
Within a graphical environment, switching to a text console requires pressing CTRL-ALT + the appropriate function key (with F7 or F1 leading to the GUI)
What does bash stand for?
Bourne Again Shell by GNU
What happens when the kernel is loaded in RAM?
It immediately initializes and configures the computer’s memory and also configures all the hardware attached to the system
What is init responsible for?
- ) Starting the system
- ) Keeping the system running
- ) Shutting it down cleanly
