This course gives an introduction to administration of the RHEL operating system using the Bash shell. Although based on Redhat (CentOS), the commands and principles learnt may also be applied to all other versions of Linux.
The course takes the format of a workshop, with a mix of lecture, working examples and practical exercises. Although the content may be customised, at least 2 days are normally needed to cover the core elements.
The course is suitable as preparation for the RHCSA examination.
Full course notes are provided along with sample script files and free software tools for use in accessing a Linux server.
The course is suitable for those who already have some knowledge of Linux as well as users new to the system.
Aims and Objectives, Schedule, Introductions, Pre-requisites, Responsibilities
Objectives, Logging On, Customising the Shell, . - dot Command, Getting Help, Command History, Command Completion, Piping - using | symbol, Redirection -using > symbol, Redirection - using >> symbol, Redirection of Errors - using 2> symbol, Wildcards - File Name Generation, Wildcards - using *, Wildcards -using ?, Wildcards - using , Extended Globbing, Vi and Vim Editors, Using vim, Command Mode - Moving the Cursor, Setting Options, Input/Replace Mode – Inserting/Changing Text, Deleting Text, Other commands, Command-line Mode – Saving/Exiting, Mapping Keys, Saving Settings, Cut and Paste Text - delete and put, Copying Text - yank and put, Comparing Files - cmp, diff, sdiff, vimdiff, Regular Expressions, Global Search Commands, Line Addresses, Global Substitution, Replacing Many Characters, Global Printing and Deleting, Why use vim?, Advanced Commands, find - Finding Files, More on Redirection, Redirecting Errors, Finding Multiple Files, Find and Execute Command, xargs -Passing Filenames, Foreground Jobs, Background Jobs - &, kill - Stopping Jobs, jobs - Job Control, Scheduling Jobs, crontab Command, mail - Reading Mail, grep - Finding Text in Files, grep - Using Regular Expressions, egrep -Expression grep, Using Filters, Backing Up Files, Permissions - File and Directory, Permissions - Evaluating, chmod - Changing Permissions, chmod – Octal Numbers, SUID Bit, umask - Default File Permissions, umask - Changing Default Permissions
Objectives, Linux Distributions, Red Hat, CentOs and Fedora?, Installation, Pre Installation, Installation Summary, Red Hat Enterprise Linux 7, The System Administrator, Understanding Superuser Status, su – Switch User, Post Installation, File System Type, Customising the Shell, . - dot Command, Backing Up Configuration Files, sudo - Commands as Root, sudo – Allowing Use, System Directory Structure, System Directory Contents, Webmin, Log Files, Logrotate, KickStart - Automated Installation, Creating a Kickstart File, Verifying the Kickstart File, Making the Kickstart File Available, Starting the Installation, Linux Install Server
Objectives, Managing Packages, Yellowdog Update Manager, Command Completion, Appling RHEL Updates, Red Hat Package Manager, Yum with RPM, Create a Local Yum Repository, Installing Software From Source, KVM Hypervisor
Startup and Shutdown
Objectives, /boot Directory, GRUB2 - GRand Unified Bootloader, The Grubby Tool, Listing the Default Kernel, Changing the Default Boot Entry, Viewing the GRUB Menu Entries, Fixing GRUB Issues, init, Upstart, systemd, Systemd Targets, Rescue Mode, Emergency Mode, Shutdown Commands
Service and Printer Management
Objectives, Overview of Services, systemctl Command, System Monitoring Tools, CUPS Printing System, Installation, Managing Printers, lpadmin - Adding a Printer, Accept and Reject, Set Default Printer, Printing Files, Enable and Disable, lpmove - Moving Files, Deleting a Printer, Web Tool
Objectives, /etc/passwd File, Checking the passwd File, Adding a User, Creating a User Manually, useradd - Creating a User, Default Values, Customising the Environment, /etc/profile, /etc/bashrc Files, /etc/skel Files, /etc/profile.d, /etc/shadow File, Password Ageing, /etc/group File, Checking the group File, usermod - Modifying a User, Locking Users, userdel - Removing Users, groupadd - Creating a Group, groupdel - Removing a Group, groupmod -Modifying a Group, newgrp - Using Groups, Change Group - chgrp, Change Ownership - chown, Disable Root Login via ssh, Access control lists, Adding New Commands
Objectives, Managing Network Connections, Configuration File, /etc/hosts File, ping - Contacting a Server, Host Information, File Transfer Between Servers, Firewalls, FirewallD, Samba Shares, Samba Testing, Network File System (NFS), Server & Client Actions, Server Actions, Client Actions, Client - Configure Automount, FTP vsftpd Server, Installing vsftp, Testing vsftpd
File System Management
Objectives, File Systems, Disc Usage, The Ext3 Filesystem, The Ext4 Filesystem, The XFS Filesystem, Understanding Inodes, Mounting File Systems, Mounted Systems, Disk Slices, umount, mount, Automounter, Preparing Disks, Creating Disk Slices, Creating a File System, Mounting the File System, Checking File Systems, The /etc/fstab File, Adding Swap Space, Recovery Workshop, Disk Quotas, ulimit, Sysctl
File System Backup
Objectives, Why Do We Backup?, What is a Backup?, Types of Backup, Logging Backups, Dump Command (EXT File Systems only), Restore Command (EXT File Systems only), Full Restore, Interactive Restore, Xfsdump (XFS File Systems only), Xfsrestore (XFS File Systems only), crontab - Scheduled Jobs, Controlling Access to cron
Objectives, Logical Volume Manager (LVM), Create Device, Physical Volumes (PV), Volume Groups (VG), Logical Volumes (LV), Make File System & Mount, Automount, Extend ext4 LV, Reduce ext4 LV, Set Size ext4 LV, Resize xfs LV, Remove the PV, LVM Snapshots, Mapped Devices
Objectives, Introduction to SELinux, Overview, Decision Making Process, Configuration Files, Contexts, Troubleshooting, Utilities, Policies and Booleans, Modules, Harden and Secure CentOS, Apache HTTP Server, Installing Apache, Testing Apache, Summary of Basic Setup, Apache Security, Appendices
Server Administration Tools, Monitoring and debugging
Main Commands, Get By In vim, Get by in nano