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You're reading from Ubuntu 20.04 Essentials A guide to Ubuntu 20.04 desktop and server editions

Product type Paperback

Published in Aug 2020

Publisher Packt

ISBN-13 9781800568525

Length 328 pages

Edition 1st Edition

Tools

Ubuntu Server

Concepts

System Administration

Author (1):

Neil Smyth

View More author details

Table of Contents (38) Chapters

1. Introduction

2. A Brief History of Linux FREE CHAPTER

3. Installing Ubuntu on a Clean Disk Drive

4. Installing Ubuntu with the Network Installer

5. Dual Booting Ubuntu with Windows

6. Allocating Windows Disk Partitions to Ubuntu

7. A Guided Tour of the GNOME 3 Desktop

8. An Overview of the Ubuntu Cockpit Web Interface

9. Using the Bash Shell on Ubuntu

10. Managing Ubuntu Users and Groups

11. Managing Ubuntu systemd Units

12. Ubuntu Software Package Management and Updates

13. Ubuntu Snap Package Management

14. Ubuntu Network Management

15. Ubuntu Firewall Basics

16. Using gufw and ufw to Configure an Ubuntu Firewall

17. Basic Ubuntu Firewall Configuration with firewalld

18. Configuring SSH Key-based Authentication on Ubuntu

19. Ubuntu Remote Desktop Access with Vino

20. Ubuntu Remote Desktop Access with VNC

21. Displaying Ubuntu Applications Remotely (X11 Forwarding)

22. Using NFS to Share Ubuntu Files with Remote Systems

23. Sharing Files between Ubuntu and Windows Systems with Samba

24. An Overview of Virtualization Techniques

25. Installing KVM Virtualization on Ubuntu

26. Creating KVM Virtual Machines using Cockpit and virt-manager

27. Creating KVM Virtual Machines with virt-install and virsh

28. Creating an Ubuntu KVM Networked Bridge Interface

29. Managing KVM using the virsh Command-Line Tool

30. An Introduction to Linux Containers

31. Working with Containers on Ubuntu

32. Setting Up an Ubuntu Web Server

33. Configuring an Ubuntu Postfix Email Server

34. Adding a New Disk Drive to an Ubuntu System

35. Adding a New Disk to an Ubuntu Volume Group and Logical Volume

36. Adding and Managing Ubuntu Swap Space

37. Ubuntu System and Process Monitoring

Index

11.3 Ubuntu systemd Target Descriptions

As previously outlined, Ubuntu can be booted into one of a number of target levels. The default target to which the system is configured to boot will, in turn, dictate which systemd units are started. The targets that relate specifically to system startup and shutdown can be summarized as follows:

• poweroff.target - This is the target in which the system shuts down. For obvious reasons it is unlikely you would want this as your default target.

• rescue.target – Causes the system to start up in a single user mode under which only the root user can log in. In this mode the system does not start any networking, graphical user interface or multi-user services. This run level is ideal for system administrators to perform system maintenance or repair activities.

• multi-user.target - Boots the system into a multi-user mode with text based console login capability.

• graphical.target - Boots the system...