Information Security and IT Risk Management

CHAPTER 3 System Administration (Part 2)

Overview

In the previous chapter, we introduced system administration and described the role that system administrators play in information security. This chapter continues the discussion of system administration by introducing a core set of technical operations used by system administrators. These operations are demonstrated using the Linux virtual machine created in the previous chapter. At the end of this chapter, you should know:

• The core components of a modern operating system
• How to use the command-line interface (CLI)
• Basic operations to navigate the filesystem
• File permissions for users and groups
• User account management
• Software management

Operating system structure

Computer operating systems are software that manage computer hardware and provide common services to user applications. Modern operating systems are made up of many separate programs (or processes) that all work together to produce the desired results. At the core, the kernel is the software which provides controls for hardware devices, manages memory, executes code on the computer's CPU, and hides the details of the underlying physical hardware from user applications. This allows application developers to ignore the details of the underlying hardware when developing applications, greatly simplifying application development.

The shell is a text-based program that allows the user to interact directly with the kernel. Common operations performed using the shell include ...