Fundamentals of Unix and Linux System Administration

Learn essential unix and linux system administration tasks, including shell scripting, user and account management, backups, and package management across Red Hat and Debian flavors.

Learn to use the man pages (manual) to find help for Linux commands, system calls, and configuration files, navigate with space and ctrl-f, and search by keyword or topic.

Master advanced man command usage, including keyword searches with man -k and title-only queries with man -f, and learn to update the man database with makewhatis.

Discover linux package management basics, including rpm and deb packages, dependency handling, and post install scripts, and why compiling from source can overwrite configs and complicate uninstall.

explores the low-level rpm and dpkg basics and shows how yum and apt-get install, upgrade, and erase packages from repositories with dependency handling.

Learn to create a local apt repository to share updates across many machines by syncing packages with apt-matter and serving them via http or ftp, and automate upgrades with cron.

Master yum plugins for faster mirrors, security updates, and delta rpm, and discover package discovery with provides, group installs, and cache cleanup for efficient Linux administration.

Learn how to automate admin tasks with shell scripting, document procedures, and schedule backups with cron, while using bash, ksh, or csh and mastering redirection, pipes, and grep.

Explore how to declare and reference variables in bash, choose quotes for values, use braces to avoid confusion, and work with environment variables like PATH and HOME in shell scripts.

Learn to use sort, unique, wc, head, tail, and grep to process text in shell scripts, pipe outputs, and monitor logs with tail -f.

Learn to create bash scripts, make them self-executable with a shebang, run via dot slash or interpreter, and use echo, printf, reads, and arguments like $0, $1, and $@.

Define bash shell functions to encapsulate code, call them in scripts, and centralize usage messages. Use local to scope variables, and apply if statements and file tests to control flow.

Explore bash loops, including for in with globbing to compress log files, and while loops for user input and infinite demon services, with sleep and timestamps.

Explore Perl as a full programming language designed for scripting within Unix and Linux, comparing it to Bash and other languages, and learn basics like scalars, arrays, semicolons, and comments.

Explain Perl arrays and hashes, including slicing arrays to extract items and using hashes with keys and values. Show access by index or key, concatenation, printing, and reading user input.

Learn how Perl handles script arguments, using @ARGV and $0, counting args with $#ARGV, and applying for, foreach, and while loops with eq/ne operators.

Discover Python basics for system administration, from installation and interactive shells to version differences between Python 2 and 3.5, and how modules, indentation, and command line arguments drive scripting.

Learn Python basics with lists, tuples, and dictionaries, plus for and while loops. Explore command line arguments and data access by index or key, and compare shell scripting with Python.

Explore startup daemons and run levels, revealing how scripts configure services at boot, then trace the boot process from BIOS and bootloader to kernel loading with Grub, including multi-boot scenarios.

Learn to boot a second operating system with grub, including Windows-first dual-boot on separate disks, and use kernel options to troubleshoot and reset root passwords in single-user mode.

Learn how Linux runlevels 0–6 define system modes, with text and i-mode, and how rc scripts and chkconfig manage startups and dependencies.

Create a simple daemon that logs the current date every second and configure it with a launcher script installed via chkconfig to run at runlevels 3, 4, and 5.

Explore ownership, root privileges, and how files and processes enforce access in Unix and Linux, including user and group IDs and real, effective, and saved IDs.

Utilize the root account's power responsibly by logging in as a normal user and using su to switch; avoid direct root login and secure ssh by disabling root access.

Configure sudoers to safely delegate root powers by granting specific commands to users or groups, enforce password prompts, and protect root access with careful visudo edits.

Master using sudo to run commands as root, explore password prompts and no-exit protections, and audit sudo activity with system logs for accountability.

Explore system accounts in unix-like systems, including uids under 100, no login shells, and no home directories, used for running daemons and printers, exempt from password aging.

Understand what a process is from the kernel, how virtual memory and pages manage resources, and how IDs, ownership, and parent‑child relations govern process privileges, including real and effective IDs.

Explore how real id, effective id, and supplementary groups determine a user's access and file permissions via the primary group, and how cpu time and nice value govern process priority.

Explore how Unix and Linux spawn processes with fork, replace them with exec, and terminate via signals like SIGINT and SIGKILL, including core dumps and orphan handling.

Learn to terminate processes with kill signals, distinguish termination behaviors, explore process states, and use ps and top to monitor, plus Linux vs Unix killall differences.

Explore the /proc virtual file system to view a running process's files and descriptors, including redirects to logs, then use estrace to trace its system calls for troubleshooting.

Explore Linux file systems, how the kernel abstracts them, and how to mount and unmount devices while navigating absolute and relative paths with proper space handling.

survey important linux directories to explain why /etc stores sensitive configuration files, contrast /var and spool data with root, and introduce device files and directory structure basics.

Explore major and minor numbers in device files under /dev and how udev maps devices. Examine unix domain sockets, named pipes, and symbolic vs hard links for IPC and libraries.

Master safe file deletion with rm, handling special filenames using -- and quotes or globs; understand Linux permissions, octal chmod modes, and recursive changes for files and directories.

Understand how file permissions differ for files vs. directories and control access with read, write, and execute. Learn setuid, setgid, and the sticky bit, plus viewing with ls.

Learn how to change file ownership and group with proper permissions, including user/root requirements, recursive changes with globbing precautions, and how umask and ACLs control default and fine-grained access.

Explain sha-512 password hashing and the shadow file, including salts that yield unique hashes per user. Highlight password policies and account safeguards like locking and avoiding empty passwords.

Explore how uid and gid identify users and groups, and how passwd maps ids to names. Learn about home directories, startup files, and using finger for user details.

Learn the login shell’s role as the command line interpreter, switch among shells such as bash and csh, and manage users, shells, and startup files.

Learn to add and manage system users with useradd or adduser, bulk create with newusers, configure home directories and shells, and handle password security, locking, and deletion.

Explore storage in Linux administration, including disks, file systems, partitions, raid, lvm, nfs or samba. Understand how the kernel auto-discovers devices and uses unique ids for mounting.

Learn to add a disk to a Linux system by creating a partition with fdisk, forming a physical volume, and creating a volume group and a logical volume.

Partition disks to divide space into primary and extended partitions, create separate file systems for root, home, var, and temp, and configure swap across multiple disks for performance and reliability.

Explore how raid manages data across multiple disks to provide protection and performance, covering raid levels 0, 1, 0+1, 5, 6, parity, mirroring, striping, and hot spares.

Create a software raid 5 array on Red Hat Linux using three 1 GB disks, partition them, assemble /dev/md0 with mdadm, format, mount, and configure persistence and monitoring.

Master linux logical volume management (lvm) by creating volume groups from physical volumes and logical volumes for flexible storage. Use snapshots for online backups and safe data migration.

Learn to resize logical volumes and volume groups in Linux, extending and shrinking file systems with lvextend and resize2fs, and understand the role of journaling in data integrity.

Explore how Linux file systems use inodes and inode tables to manage files, inspect inode usage with df -i, and understand mounting with options like noexec, nodev, noauto.

Explore how to build a cost-effective storage area network using iSCSI over IP, configuring an initiator and a target, enabling CHAP authentication and iqn naming, and mounting remote storage.