Linux Service Management Made Easy with systemd: Advanced techniques to effectively manage, control, and monitor Linux systems and services

Cover
Copyright
Contributors
Table of Contents
Preface
Section 1: Using systemd
Chapter 1: Understanding the Need for systemd
	Technical requirements
	The history of Linux init systems
	The shortcomings of SysV Init and upstart
	The advantages of systemd
		systemd's simplicity
		systemd's consistency
		systemd's performance
		systemd security
	The systemd controversy
	Summary
	Questions
	Answers
	Further reading
Chapter 2: Understanding systemd Directories and Files
	Technical requirements
	Understanding the systemd configuration files
	Understanding the systemd unit files
		Types of unit files
	Understanding the systemd executables
	Summary
	Questions
	Answers
	Further reading
Chapter 3: Understanding Service, Path, and Socket Units
	Technical requirements
	Understanding service units
		Understanding the Apache service file
		Understanding the Secure Shell service file
		Understanding the timesyncd service file
	Understanding socket units
	Understanding path units
	Summary
	Questions
	Answers
	Further reading
Chapter 4: Controlling systemd Services
	Technical requirements
	Verifying the status of a service
	Starting, stopping, and reloading services
	Enabling and disabling services
	Killing a service
	Masking a service
	Summary
	Questions
	Answers
	Further reading
Chapter 5: Creating and Editing Services
	Technical requirements
	Editing an existing service
		Creating a partial edit to the [Install] section
		Creating a partial edit to the [Service] section
		Creating a full edit
	Creating a new service
	Changing the default systemd editor
	Creating a new container service with podman
	Summary
	Questions
	Answers
	Further reading
Chapter 6: Understanding systemd Targets
	Technical requirements
	Understanding the purpose of systemd targets
	Understanding the structure of a target file
		Understanding the sockets.target file
		Understanding dependencies in the sshd.service file
	Comparing systemd targets to SysVinit runlevels
	Understanding target dependencies
	Changing the default target
	Temporarily changing the target
	Summary
	Questions
	Answers
	Further reading
Chapter 7: Understanding systemd Timers
	Technical requirements
	Comparing systemd timers with cron
		Viewing timer information
	Understanding timer options
		Understanding monotonic timers
		Understanding real-time timers
		Understanding calendar events for real-time timers
	Creating timers
		Creating a system-level timer
		Creating a user-level timer
	Summary
	Questions
	Answers
	Further reading
Chapter 8: Understanding the systemd Boot Process
	Technical requirements
	Comparing SysV bootup and systemd bootup
		Understanding SysV and systemd bootup similarities
		Understanding the SysV bootup process
		Understanding the systemd bootup process
	Analyzing bootup performance
	Some differences on Ubuntu Server 20.04
	Understanding systemd generators
		Understanding mount units
		Understanding backward compatibility
	Summary
	Questions
	Answers
	Further reading
Chapter 9: Setting System Parameters
	Technical requirements
	Setting the locale parameter
		Understanding the locale
		Changing the default locale on the Alma machine
		Changing the default locale on Ubuntu
	Setting time and timezone parameters
	Setting the hostname and machine information
		Viewing the information
		Setting the information
	Summary
	Questions
	Answers
	Further reading
Chapter 10: Understanding Shutdown and Reboot Commands
	Technical requirements
	Shutting down with systemctl
	Halting with systemctl
	Rebooting with systemctl
	Using shutdown instead of systemctl
	Running a job before shutting down
	Summary
	Questions
	Answers
	Further reading
Section 2: Understanding cgroups
Chapter 11: Understanding cgroups Version 1
	Technical requirements
	Understanding the history of cgroups
	Understanding the purpose of cgroups
	Understanding the structure of cgroups Version 1
	Understanding the cgroup filesystem
	Summary
	Questions
	Answers
	Further reading
Chapter 12: Controlling Resource Usage with cgroups Version 1
	Technical requirements
	Understanding resource controllers
		Examining the resource controllers
		Preparing for the demos
	Controlling CPU usage
		Controlling Vicky's CPU usage
		Controlling CPU usage for a service
	Controlling memory usage
	Controlling blkio usage
		Setting a blkio limit for Vicky
		Setting a blkio limit for a service
	Understanding pam_limits and ulimit
		The ulimit command
		The pam_limits module
	Summary
	Questions
	Answers
	Further reading
Chapter 13: Understanding cgroup Version 2
	Technical requirements
	Understanding the need for Version 2
		Version 1 complexity
		Version 1 attribute filenames
		No support for rootless containers
	Understanding the improvements in cgroup Version 2
	Setting resource limits on rootless containers
	Understanding cpuset
	Converting RHEL 8-type distros to cgroup version 2
	Summary
	Questions
	Answers
	Further reading
Section 3: Logging, Timekeeping, Networking, and Booting
Chapter 14: Using journald
	Technical requirements
	Understanding the pros and cons of rsyslog
	Understanding the pros and cons of journald
	Understanding journald on Ubuntu
	Understanding journald on RHEL-type systems
	Using journalctl
		Searching for and viewing log data with journalctl
	Sealing journald log files for security
	Setting up remote logging with journald
	Summary
	Questions
	Answers
	Further reading
Chapter 15: Using systemd-networkd and systemd-resolved
	Technical requirements
	Understanding networkd and resolved
	Understanding Netplan on Ubuntu
		Viewing installer-generated Netplan configurations
		Creating Netplan configurations
	Understanding networkd and resolved on RHEL-type machines
	Using networkctl and resolvectl
	Viewing the networkd and resolved unit files
	Summary
	Questions
	Answers
	Further reading
Chapter 16: Understanding Timekeeping with systemd
	Technical requirements
	Understanding the importance of accurate time
	Comparing NTP implementations
	Understanding chrony on the AlmaLinux machine
		The chronyd.service file
		The chrony.conf file
		Setting up a chronyd time server
		Using chronyc
	Understanding systemd-timesyncd
		The systemd-timesyncd.service file
		The timesyncd.conf file
		Using timedatectl
		Configuring Ubuntu to use chrony
	Understanding the Precision Time Protocol
		An overview of PTP
		Installing PTP
		Configuring PTP with software timestamping on AlmaLinux
		Configuring PTP with hardware timestamping on AlmaLinux
		Configuring PTP with software timestamping on Ubuntu
		Configuring PTP with hardware timestamping on Ubuntu
	Summary
	Questions
	Answers
	Further reading
Chapter 17: Understanding systemd and Bootloaders
	Technical requirements
	Understanding the basic computer architecture
	Understanding GRUB2
		Comparing GRUB2 on BIOS and EFI/UEFI systems
		GRUB2 on BIOS-based and EFI/UEFI-based Ubuntu machines
	Understanding systemd-boot
	Understanding Secure Boot
	Summary
	Questions
	Answers
	Further reading
Chapter 18: Understanding systemd-logind
	Technical requirements
	Understanding the need for a new login service
	Understanding systemd-logind.service
		The Alma Linux systemd-logind.service file
		The Ubuntu Server systemd-logind.service file
	Understanding logind.conf
		Virtual terminals
		Keeping user processes going after logout
		Power management directives
		The IdleAction directives
	Understanding loginctl
	Understanding polkit
	Summary
	Questions
	Answers
	Further reading
Index
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