Linux / UNIX keyboard.

Linux Server Administration

Course 144 Supplemental Material

My main Linux page is a collection of links to several pages on Linux and related Unix-family topics. Some of them are especially related to the course, going deeper than we have time to go during the course.

Setting up a Test / Practice System

Get the CentOS "Everything" ISO image and install a basic Desktop system. Or, better yet I think, an Oracle Linux image. Do this on a computer that can get out to the Internet. The directory /etc/yum.repos.d/ will contain definitions of the CentOS software repositories. Now you can use yum and install whatever else you want.

You could build it on a Oracle VirtualBox virtual machine, on a Raspberry Pi (get the Oracle Linux Raspberry Pi image), or on spare hardware.

Data You Used

I'm not sure how helpful this will really be, but here is the collection of data you used. All of /usr/local/src from your system, plus /export from the tux classroom server.

Course 144 Data

Commands you learned

This list of system administration commands is really a one-page summary of all the commands we use in the course.

System Administration Commands

Upgrading RHEL / Oracle / CentOS 6–7–8–9

Here's how to upgrade through RHEL/Oracle/CentOS 6–7–8–9, organized by the course chapters.

How to upgrade Red Hat / Oracle / CentOS 6–7–8–9

Chapter 1 — Configuring a Linux Server

We start talking about SysFS in chapter 1, so we can talk about devices, exploring the PCI, USB, and SCSI buses, and other details of the kernel and hardware through later chapters.

Exploring SysFS, Buses, and Devices

Chapter 2 — Booting and Service Control

"How does Linux boot?" Here is everything from firmware through service control.

How Linux Boots

Chapter 3 — Process Control and Logging

Chapter 3 covers (briefly) Rsyslog. This page explains how to set up authenticated and encrypted TLS connections to a central log collector.

Rsyslog over TLS

Chapter 4 — Users and Groups

The course mentions that Linux can be federated into an Active Directory domain (or realm). It also mentions that you can build an Active Directory domain controller with Samba 4. Here is how to do those things:

Build an Active Directory domain controller with Samba

Chapter 5 — Storage: Devices, LVM, and File Systems

Chapter 5 is about storage. Here's how to set up encrypted file systems. It also adds how to do it in the cloud.

Also in chapter 5, we talked about LVM or Logical Volume Management. Red Hat's installer prefers one large root file system based on LVM. Here's how to rescue a disassembled system with an LVM root file system when you have lost track of which physical disk is which.

External multi-terabyte drives may take some extra work to use them on a non-Windows system.

Digital cameras used to appear as USB block storage devices, but most newer ones do not. Android smart phones are more different yet.

Encrypted File Systems Rescue LVM Root File System Using External Multi-Terabyte Drives Digital Cameras and Linux Android Smart Phones and Linux

Chapter 6 — Managing Software Packages

Chapter 6 explains rpm and yum in detail, and dpkg and apt/apt-get briefly. Here is a "phrase book" for package management with those on Linux, and also package management on BSD and Solaris.

Package Management on Linux, BSD, and Solaris

Here is how to add the additional repos to get multimedia support on RHEL and other distros:

Add MP3 / MPEG Support to RHEL, CentOS, Oracle Linux, & Scientific Linux

Chapter 7 — Building Software from Source

In chapter 7 we build an RPM package from source. Here's how to create and use patch files for RPM packages.

How to Create and Use Patch Files for RPM Packages

Chapter 8 — Configuring Network Connections

Chapter 8 describes the relatively new networking commands, ip for most tasks plus a few other commands. Here are the networking commands for Linux, Android (almost but not quite identical), UNIX, macOS, Windows, and Cisco IOS.

Cable modems may negotiate a small Ethernet frame size that prevents Linux from bringing up IPv6. Here's how to run IPv6 on cable modems with Linux. That page also explains the "unreachable" routes you see in the IPv6 routing table.

Networking Commands IPv6 on Cable Modems

Chapter 9 — Controlling Network Services

Here's how to cautiously set up SSH.

How to Configure and Use SSH Service

Chapter 10 — File and Print Services

Canon PIXMA MG multi-function printer/scanner devices require a little extra care.

So may other scanners, as you have to add associated firmware.

Canon PIXMA MG Multi-Function Devices and Linux Solving the "invalid argument" Error with SANE

Chapter 12 — The Linux Kernel

In chapter 12 we build and install a new kernel. This page adds a few more details that we just don't have time to also cover in the course.

How to Build Linux Kernels

I have pages with suggestions on tuning the kernel and other components for better network security and both network and storage performance.

Tune the Kernel for Security Tune the Kernel for Performance

The kernel implements various random pseudo-devices, and handles the hardware random number generator if you have one. Here are details on the random devices.

Linux Random Devices and Entropy