LFCS Exam curriculam and areas tested:
- Essential commands - 20%
- Operations Deployment - 25%
- Users and groups - 10%
- Networking - 25%
- Storage with RAID etc - 20%
This document starts with the essentials video course training and then followed by the system administrator course. This doc is mainly contains notes from video courses.
Linux Core Concepts
Introduction to linux kernel
Simily put, consider a library with all kinds of books, study guides, workstations etc. But these resources are limited. Without a librarian, we would not have any management on these resources, but librarian manages, keeps track of all the books, who should get what and who should get next. In Computers, librarian is the kernel that manages the applications process.
kernal is mainly responsible for memory management, process management, device drivevrs and system call and security. Linux kernal is monolithic, meaning it carries all the actions and functionality by itself and it is also moduler.
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# to see which kernel is running
uname
# To get the version of the kernel
uname -r
Check out Kernal Open source repo. One of the important functions of the kernel is memory management.
memory is divided into two spaces:
- kernel space
- User space
kernal space has unlimited hardware resources. No restrictions but user space is mainly for application processes. if we look at the flow, application programs from the user space calls go to kernel space which looks where the file or requested hardware/software is located to provision, if available.
