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


In Linux, each file, directory, and other system object has a designated owner and group. This is the most fundamental aspect of system security that safeguards users from one another. Different sorts of access to read from, write to, or execute files can be given to owners, group members, and everyone else. In Linux, these are commonly referred to as file permissions.

The following commands are used to manage ownership and set permissions:

  • Change file permissions with chmod
  • Change the file owner with chown
  • Change group ownership with chgrp
  • Print the user and group IDs with id

Typically, the user who created a file is its owner, and the group attached to that owner is its primary group (at least initially). Let’s create a testfile file in the /tmp directory as an example:

$echo "This is a test file" >  testfile
$ls -l testfile
-rw-rw-r-- 1 packt packt 20 Feb  6 16:37 testfile

The first character...