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Linux Service Management Made Easy with systemd

You're reading from   Linux Service Management Made Easy with systemd Advanced techniques to effectively manage, control, and monitor Linux systems and services

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Product type Paperback
Published in Feb 2022
Publisher Packt
ISBN-13 9781801811644
Length 420 pages
Edition 1st Edition
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Author (1):
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Donald A. Tevault Donald A. Tevault
Author Profile Icon Donald A. Tevault
Donald A. Tevault
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Toc

Table of Contents (23) Chapters Close

Preface 1. Section 1: Using systemd
2. Chapter 1: Understanding the Need for systemd FREE CHAPTER 3. Chapter 2: Understanding systemd Directories and Files 4. Chapter 3: Understanding Service, Path, and Socket Units 5. Chapter 4: Controlling systemd Services 6. Chapter 5: Creating and Editing Services 7. Chapter 6: Understanding systemd Targets 8. Chapter 7: Understanding systemd Timers 9. Chapter 8: Understanding the systemd Boot Process 10. Chapter 9: Setting System Parameters 11. Chapter 10: Understanding Shutdown and Reboot Commands 12. Section 2: Understanding cgroups
13. Chapter 11: Understanding cgroups Version 1 14. Chapter 12: Controlling Resource Usage with cgroups Version 1 15. Chapter 13: Understanding cgroup Version 2 16. Section 3: Logging, Timekeeping, Networking, and Booting
17. Chapter 14: Using journald 18. Chapter 15: Using systemd-networkd and systemd-resolved 19. Chapter 16: Understanding Timekeeping with systemd 20. Chapter 17: Understanding systemd and Bootloaders 21. Chapter 18: Understanding systemd-logind 22. Other Books You May Enjoy

The history of Linux init systems

So, what is an init system? Well, init is short for initialization. An init system, then, initializes the operating system upon bootup. After the bootup has completed, the init system will continue working, managing system processes and services. Each system process is assigned a process ID number, or PID. The init process is always PID 1, and every other process that gets started on the system is either a child or a grandchild of the init process.

For many years, the SysV Init system was the primary init system for Linux-based operating systems (SysV is short for System 5. The V is the Roman numeral for 5). SysV init was originally developed by Bell Labs engineers for the Unix operating system, all the way back in the early 1970s. (At that time, I was a young pup in junior high school, and I still had a full head of hair.)

Note

There are actually a few more Linux init systems besides the ones that I'm mentioning here. But these were the most commonly used ones in the pre-systemd days.

SysV init worked well in its day, but it was never perfect. Nowadays, with new high-performance hardware, SysV init has shown both its age and its deficiencies. The first attempt to come up with something better occurred in July 2009, when Ubuntu engineers released the first version of the upstart init system. Although it was better than SysV, it still had its share of problems, especially the early versions which were quite buggy.

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Linux Service Management Made Easy with systemd
Published in: Feb 2022
Publisher: Packt
ISBN-13: 9781801811644
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