Book Image

Linux Service Management Made Easy with systemd

4 (1)
Book Image

Linux Service Management Made Easy with systemd

4 (1)

Overview of this book

Linux Service Management Made Easy with systemd will provide you with an in-depth understanding of systemd, so that you can set up your servers securely and efficiently.This is a comprehensive guide for Linux administrators that will help you get the best of systemd, starting with an explanation of the fundamentals of systemd management.You’ll also learn how to edit and create your own systemd units, which will be particularly helpful if you need to create custom services or timers and add features or security to an existing service. Next, you'll find out how to analyze and fix boot-up challenges and set system parameters. An overview of cgroups that'll help you control system resource usage for both processes and users will also be covered, alongside a practical demonstration on how cgroups are structured, spotting the differences between cgroups Version 1 and 2, and how to set resource limits on both. Finally, you'll learn about the systemd way of performing time-keeping, networking, logging, and login management. You'll discover how to configure servers accurately and gather system information to analyze system security and performance. By the end of this Linux book, you’ll be able to efficiently manage all aspects of a server running the systemd init system.
Table of Contents (23 chapters)
1
Section 1: Using systemd
12
Section 2: Understanding cgroups
16
Section 3: Logging, Timekeeping, Networking, and Booting

Understanding the importance of accurate time

Accurate timekeeping on computers wasn't always real important. My very first computer job involved working with a pair of transistorized computers that were each the size of a refrigerator, and that had orders of magnitude less processing power than a modern smartphone. There was no hardware clock, and there was no NTP. Every time we rebooted these beasts, we just looked at our notoriously inaccurate wall clock and manually entered the time from it. Things didn't change much with the early personal computers. I mean, you still had to set the time manually, but they did eventually come with battery-powered hardware clocks that would still keep time when you shut the computers down.

Nowadays, it's critically important for computers to maintain accurate time. Scientific computing, log keeping, database updating, and financial transactions all require it. Certain security protocols, such as Kerberos, DNSSEC, and Transport...