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 journald on Ubuntu

On Ubuntu systems, the journald and rsyslog services are both enabled by default, and they both run as completely independent entities. The journald logs are persistent, which means that they are permanently stored on disk, instead of getting deleted every time you shut down the machine. The rsyslog log files are also present, and they get rotated every week.

Two things make the journald log files persistent. First, is the very first configuration option in the /etc/systemd/journald.conf file, which looks like this:

[Journal]
#Storage=auto
. . .
. . .

When you look at this whole file, you'll see that every line in it is commented out. This just means that all of these options have been set to their default values. To change something, just uncomment the line and change the value. However, we don't need to do anything with this #Storage=auto line. The auto here means that if the /var/log/journal/ directory exists, then journald will...