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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

5.3 Changing the Default Boot Option

When the system starts, the boot options screen will appear and wait 10 seconds for the user to make an operating system choice. If no selection has been made before the timeout elapses, the default operating system will be started. On a newly configured system, the default operating system will be the standard Ubuntu image. This default can, however, be changed from within Ubuntu.

A range of boot configuration options (including the 10 second timeout and the boot settings outlined in “Installing Ubuntu on a Clean Disk Drive”) are declared in the /etc/default/grub file which reads as follows on a new installation:

GRUB_DEFAULT=0

GRUB_TIMEOUT_STYLE=hidden

GRUB_TIMEOUT=10

GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`

GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash”

GRUB_CMDLINE_LINUX=””

The first step in changing the default boot system is to declare the GRUB_SAVEDEFAULT...