Book Image

Ubuntu 20.04 Essentials

By : Neil Smyth
Book Image

Ubuntu 20.04 Essentials

By: Neil Smyth

Overview of this book

Ubuntu is undeniably one of the most highly regarded and widely used Debian-based Linux distributions available today. Thanks to its ease of use and reliability, Ubuntu has a loyal following of Linux users and an active community of developers. Ubuntu 20.04 Essentials is designed to take you through the installation, use, and administration of the Ubuntu 20.04 distribution in detail. For beginners, the book covers topics such as operating system installation, the basics of the GNOME desktop environment, configuring email and web servers, and installing packages and system updates. Additional installation topics such as dual booting with Microsoft Windows are also covered along with crucial security topics such as configuring a firewall and user and group administration. For the experienced user, the book delves into topics such as remote desktop access, the Cockpit web interface, logical volume management (LVM), disk partitioning, and swap management. Further, it also explores KVM virtualization, Secure Shell (SSH), Linux containers, and file sharing using both Samba and NFS to provide a thorough overview of this enterprise-class operating system.
Table of Contents (38 chapters)
38
Index

30.1 Linux Containers and Kernel Sharing

In simple terms, Linux containers can be thought of as a lightweight alternative to virtualization. In a virtualized environment, a virtual machine is created that contains and runs the entire guest operating system. The virtual machine, in turn, runs on top of an environment such as a hypervisor that manages access to the physical resources of the host system.

Containers work by using a concept referred to as kernel sharing which takes advantage of the architectural design of Linux and UNIX-based operating systems.

In order to understand how kernel sharing and containers work it helps to first understand the two main components of Linux or UNIX operating systems. At the core of the operating system is the kernel. The kernel, in simple terms, handles all the interactions between the operating system and the physical hardware. The second key component is the root file system which contains all the libraries, files and utilities necessary...