Book Image

Linux for System Administrators

By : Viorel Rudareanu, Daniil Baturin
Book Image

Linux for System Administrators

By: Viorel Rudareanu, Daniil Baturin

Overview of this book

Linux system administration is an essential aspect of maintaining and managing Linux servers within an organization. The role of a Linux system administrator is pivotal in ensuring the smooth functioning and security of these servers, making it a critical job function for any company that relies on Linux infrastructure. This book is a comprehensive guide designed to help you build a solid foundation in Linux system administration. It takes you from the fundamentals of Linux to more advanced topics, encompassing key areas such as Linux system installation, managing user accounts and filesystems, networking fundamentals, and Linux security techniques. Additionally, the book delves into the automation of applications and infrastructure using Chef, enabling you to streamline and optimize your operations. For both newcomers getting started with Linux and professionals looking to enhance their skills, this book is an invaluable hands-on guide with a structured approach and concise explanations that make it an effective resource for quickly acquiring and reinforcing Linux system administration skills. With the help of this Linux book, you’ll be able to navigate the world of Linux administration confidently to meet the demands of your role.
Table of Contents (21 chapters)
Part 1: Linux Basics
Part 2: Configuring and Modifying Linux Systems
Part 3: Linux as a Part of a Larger System

Understanding the ring buffer in Linux

When a computer is powered on, several events occur in a specific order; in Linux and Unix-like systems, these activities are referred to as booting and startup, respectively.

After the initialization of the system has been completed by the boot procedures (BIOS or UEFI, MBR, and GRUB), the kernel is loaded into memory, the initial ramdisk (initrd or initramfs) is connected to the kernel, and systemd is launched.

The OS is handed over to the startup routines, which finish the setup. When a system is first booted, it may take a while for logging daemons such as syslogd and rsyslogd to become operational. The kernel features a ring buffer that it employs as a message cache to ensure that critical error messages and warnings from this phase of initialization are not lost.

A ring buffer is a special area of memory where messages can be stored. It has a standard size and straightforward construction. When it reaches capacity, newer messages...