Chapter1(1) (1)

Chapter 1: Where to Start

Outline

• What is a System Administrator?

• Essential Duties of a System Administrator

• Linux Distributions

• Notation and Typographical Conventions

• Units

• Man Pages and Other On-line Documentation

• Other Authoritative Documentation

• Other Sources of Information

• Ways to find and Install Software

• Where to host

• Specialization and Adjacent Disciplines

What is a System Administrator?

• A system administrator (sysadmin) is responsible for:

  • Upkeep, configuration, and reliable operation of computer systems.

  • Managing multi-user computers like servers.

  • Source: Wikipedia, 2018.

Essential Duties of a System Administrator (1)

• Key responsibilities include:

  • Controlling access to systems

  • Adding and configuring hardware

  • Automating routine tasks

  • Overseeing backups

  • Installing and upgrading software

  • Monitoring system performance and security

  • Troubleshooting system issues

  • Documenting processes and configurations

  • Collaborating with vendors

  • Responding to emergencies or "fire fighting" incidents.

Essential Duties of a System Administrator (2)

• Responsibilities may be distributed among team members:

  • It is essential for at least one person to have comprehensive knowledge of all components.

  • This ensures tasks are performed correctly and consistently.

Linux Distributions (1)

• A Linux distribution comprises:

  • The Linux kernel (core of the operating system)

  • Various software packages providing commands and functionalities.

• All distributions share the same kernel lineage but may differ in:

  • Package format

  • Type and number of packages

  • Focus and support.

Linux Distributions (2)

• Hundreds of independent Linux distributions exist:

  • Distributions derived from Debian and Red Hat lineages are gaining predominance in production environments.

  • Differences among Linux distributions are generally minor, often revolving around installation ease and available software libraries.

Linux Distributions (3)

• Major distributions typically feature:

  • Simple installation procedures

  • Desktop environments

  • Package management systems.

• You can test distributions via cloud instances or local VMs.

• Choosing a distribution signifies an investment in a vendor's methodology.

Linux Distributions (4)

• Important questions to evaluate a distribution:

  • Will it be supported in five years?

  • Is the vendor prompt with security updates?

  • Is there an active community and good documentation?

  • What support is available and at what cost?

Linux Distributions (5)

Example Systems Used in this Book

• Featured distributions include:

  • Debian GNU/Linux

  • Ubuntu Linux

  • Red Hat Enterprise Linux (RHEL) and CentOS

  • FreeBSD

Red Hat Enterprise Linux

• Red Hat, a leading player in the Linux ecosystem for over two decades:

  • Dominates the open source software market.

  • RHEL targets production environments in large enterprises requiring support services.

• RHEL is open-source but requires a paid license.

• Fedora serves as a test bed for innovations before they reach RHEL.

Notation and Typographical Conventions

• Shell prompt notation:

  • $: Indicates a normal, unprivileged user.

  • #: Indicates the shell prompt for the root user.

• Common shell globbing characters:

  • *: Matches zero or more characters.

  • ?: Matches exactly one character.

  • ~: Represents the current user's home directory.

  • ~user: Refers to another user's home directory.

Units

Man Pages and Other On-line Documentation (1)

• Man pages, accessible via the man command, provide concise descriptions of:

  • Commands

  • Drivers

  • File formats

  • Library routines.

Man Pages and Other On-line Documentation (2)

• Organization of Man Pages:

  • Linux divides man pages into sections, though the structure isn't crucial for most topics.

Man Pages and Other On-line Documentation (3)

• How to read man pages:

  • Run man title to view specific manual pages.

  • Titles usually represent commands, devices, files, or library routines.

  • Man pages searched in numeric order, prioritizing sections describing commands (sections 1 and 8).

  • man -k keyword or apropos keyword lists man pages containing the keyword.

Man Pages and Other On-line Documentation (4)

• Storage of man pages:

  • Source code is usually stored under /usr/share/man and compressed using gzip.

  • man command decompresses them on-the-fly.

Other Authoritative Documentation (1)

• Man pages provide only a part of the official documentation.

• Additional documentation is often scattered on the web.

• Includes system-specific guides.

Other Authoritative Documentation (2)

• Package-specific documentation:

  • Maintained by individuals or third parties like the Internet Systems Consortium and Apache Software Foundation.

  • Supplemental materials include white papers and technical reports.

• Books:

  • O’Reilly publications are widely respected in the tech industry.

• RFC Publications:

  • This category is authoritative and useful for system administrators.

Other Sources of Information (1)

• Keeping current:

  • Social media platforms like Twitter and Reddit host active communities with valuable insights.

Other Sources of Information (2)

• HowTos and reference sites:

  • Contain guides, tutorials, and articles on executing specific tasks in UNIX and Linux environments.

Other Sources of Information (3)

• Conferences:

  • Excellent networking opportunities.

  • Offer insights into technology trends, training, certifications, and learnings on latest products and services.

Ways to Find and Install Software (1)

• Modern operating systems use packages that can be installed independently.

• Default installations provide basic packages that can be expanded or contracted as needed.

Ways to Find and Install Software (2)

• Adding new software:

  • Determine the canonical name of the software package required.

  • Commands such as the installation of tcpdump exemplify this process.

• Building software from source and installing via a web script are alternative methods.

Where to Host

• Operating systems and software can be hosted at:

  • Private data centers

  • Co-location facilities

  • Cloud platforms (recommended for new projects)

• Cloud hosting advantages include:

  • No capital expenses

  • Low initial operating costs

  • No hardware management required

  • Scalable storage, bandwidth, and compute options

  • Ready-made solutions for common needs like databases and monitoring.

Specialization and Adjacent Disciplines

• System administrators work alongside various roles within IT:

  • DevOps

  • Site reliability engineers

  • Security operations engineers

  • Network administrators

  • Database administrators

  • Network operations center (NOC) engineers

  • Data center technicians

  • Architects.

• Specialization in areas can enhance efficacy.

• The overarching goal is achieving organizational objectives.