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)
1
Part 1: Linux Basics
7
Part 2: Configuring and Modifying Linux Systems
13
Part 3: Linux as a Part of a Larger System

Active/backup configurations and load balancing with Keepalived

A Linux server that is set up as a load balancer for multiple worker servers and keeps the service available, even if any of those workers fail. However, the load balancer itself becomes a single point of failure in that scheme, unless the administrator also takes care to provide a failover mechanism for multiple balancers.

The usual way to achieve failover is by using a floating virtual IP address. Suppose www.example.com is configured to point at 192.0.2.100. If you assign that address directly to a load-balancing server in a 192.0.2.0/24 network, it becomes a single point of failure. However, if you set up two servers with primary addresses from that network (say, 192.0.2.10 and 192.0.2.20), you can use a special failover protocol to allow two or more servers to decide which one will hold the virtual 192.0.2.100 address and automatically transfer it to a different server if the primary server fails.

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