CompTIA Linux+ (LX0-103 and LX0-104) (Part 1 of 2)

Debian is a customizable, powerful Linux distribution developed by a large open-source community. Backtrack and Helix show purpose-built tools for security testing and forensics, guiding your choice by goals.

Compare closed source and open source licensing, learn GPL and LGPL implications, and see how permissive licenses like MIT and Apache govern use, modification, and distribution.

Gather hardware details and drivers during pre-installation to ensure Linux compatibility on servers, including interrupt settings and IP addresses; choose installation destination and partitioning with dual-boot or CD options.

Explore installation types such as CDs, DVDs, ISO files, and USB boot media, including live CD/DVD with RAM drive, and net installation that downloads the rest via network or NFS.

Explore partitioning as a key pre-install step by using non-destructive tools like parted or gparted to create or resize partitions during installation, including resizing Windows partitions.

Join a practical linux installation in a vmware virtual machine for the CompTIA Linux+ course, using a fedora 12 iso to set memory and disk, then explore grub and commands.

Introduce the graphical user interface, the most comfortable and familiar part of any operating system. Explore how the graphical user interface shapes user interaction and navigation.

Explore the KDE desktop environment, a Windows-like graphical interface with the K button and K bar start menu, and its support for up to four customizable desktops.

Explore how Linux integrates with shells and GUIs, interact with hardware, manage file systems, and run applications like OpenOffice and Firefox, while server tools handle user management, network and monitoring.

Demonstrate named pipes (fifos) to transfer data between shells by creating a fifo, redirecting command output into it, reading from it with cat, then removing the pipe.

Explore linux help commands and the manual, showing piping to more for paged output, searching within manual pages, and quitting with q while inspecting sections like locale.

Explore how the GUI is composed, how it works, and how it interacts with Windows in the kernel, plus common applications and the command line interface.

Master the cd command to navigate directories using absolute paths and relative paths, move up with dot dot, use dot for the current directory, and understand permissions and root access.

Learn to use pushd and popd to create memory-stored directory references, quickly move between frequently used directories, with tips to use history and the up arrow to recall cd commands.

Demonstrate creating hard and symbolic links in Linux using the ln command and GUI tools; verify links with cat and ls, and show how moving a linked file affects accessibility.

Explore file metadata by using the RLS command with the Lf option to display long information, including permissions, links, owner and group, size, date, and file type.

Mount volumes like optical and USB drives into a single root directory with the mount command, using type, device file, and mount point options; desktop systems often mount cds automatically.

Learn to perform privilege escalation by switching from a regular user to root with su, or by using sudo to run commands like mount and unmount as root.

Explore Linux file systems, directories, and mounting drives, and practice creating, editing, copying, and deleting files manually using absolute and relative paths, including cd commands, in the shell.

Delve into authentication, users and groups. Explore the basics of authorization and triple A concepts, with accounting and logging addressed later.

Create and manage user accounts from the command line, inspecting login definitions, aging controls, and password and shadow files, using useradd and adduser to set home directories and IDs.

Explore GUI admin tools for adding a new user account, ensure it includes group assignments and consistent, correct configuration, and learn when a command-line script is faster for bulk migrations.

Explore safe methods to modify user accounts using the usermod command, updating home directories, primary groups, logins, usernames, and shells while avoiding direct edits to password or shadow files.

Delete users and groups with userdel and groupdel, after locking accounts and verifying changes in /etc/shadow and /etc/passwd. Confirm removals and handle non-existent users, noting Linux is case sensitive.

Explore how Linux file ownership differs from Windows ACL entries, showing how the owner and primary group determine permissions and how the owner can set or change them.

Explore the difference between shell and environmental variables, their lifetimes and scope, and examine common vars like path, home, mail, and prompt using the set command.

Set a variable by naming it, assigning a value with equals, for your custom scripts. View it with echo $var and export to make it permanent, at creation or later.

Learn how the path sets the search order for executables, with directories like /home, local/bin, and user bin, and how to append to the path or use full paths.

Learn how a prompt conveys username, hostname, and current directory to help you navigate, especially when you are remotely connected, and how you can customize it for usefulness and clarity.

Explore how to use GNOME's GUI to adjust screen resolution, refresh rate, and rotation. Choose between system-wide or user-specific defaults.

Explore appearance preferences in Linux, including themes, backgrounds, and font options, mirroring a Windows environment. Change background colors and downloadable themes to improve focus with solid, light colors.

Configure mouse preferences to tailor input, including ambidextrous use, left- or right-handed setups, and pointer speed, while understanding click behaviors and efficient movement with a mouse pad.

Configure the mouse and keyboard settings, including handedness, pointer visibility, and double-click speed. Explore keyboard layouts and regional options, such as the United States standard and Dvorak.

Start the X Windows GUI using start X on older Linux systems. Turn off the desktop management with stop or stop X from the init.d/gdm directory, using root or sudo.

Watch how to install a package using the synaptic package manager GUI: browse categories such as games, search for items, mark affected components, and apply changes to complete installation.

Use the command line to remove packages with apt get remove and auto remove, review with synaptic, mark for removal, apply, and be careful not to delete components like asteroids.

Explore source code software, enabling downloads as text files instead of bulky install packages, and learn how missing libraries during compilation can stress users in the Linux environment.

Download a source code tarball from SourceForge, extract it with tar, install the lib SDL development package, configure, compile with make, and install the program on Linux.

Learn system configurations for Linux hardware, formatting drives, creating partitions and volumes, mounting and auto-mount, plus quotas, swap, RAID-based recovery, and recognizing USB, CD-ROM, and PCI devices.

Explore drive components like platters, a center spindle, and a read/write head on an arm that moves to tracks and sectors, and note how rpm affects seek time and performance.

Explore drive components, compare hard disk drives with solid state drives, and learn how to designate storage by volumes and partitions for Linux systems.

Understand that partitioning a single drive does not increase capacity or speed; use root and swap partitions to organize files and virtual memory, and consider separate drives for true performance.

Use fdisk to create and format partitions, describe drive geometry, and specify partition size and name, logically partitioning the drive into distinct partitions.

Explore parted, a text mode partition editor, to create partitions and file systems from the command line by specifying the /dev device, file system type, and start/stop addresses.

Demonstrate mounting an iso as a loop device in Debian, creating a loop test directory, mounting and navigating the loop file system, and unmounting to use virtual disks.

Set quotas to limit disk space per user or group based on file ownership, choosing hard or soft limits, and manage them via FS tab file in the Etsy folder.

Enable quotas by adding entries to the fstab file to set space limits for users or groups. Learn how to configure quota entries in fstab to manage disk usage.

Learn to use the edquota tool to rewrite the fstab file, leveraging a vi-like interface and mastering edit mode and command mode for effective quota management.

Learn how disk arrays use redundancy to expand storage beyond a single drive and maintain data access during failures, delivering fault tolerance and high uptime through raid types.

Learn to view PCI devices with the ls PCI command and its verbose mode, and inspect bus PCI location to see what’s found, defined, and hooked up to your system.

Examine Linux processes and module management, identifying what processes are, how to view them, kill or adjust priorities, and how to view kernel information and manage modules.

ps aux outputs per‑process cpu and memory usage to identify misbehaving processes slowing the system; analyze start time, user, and related processes to decide on termination or priority adjustments.

Demonstrates viewing processes and devices with ps and top, using options for full details and paging, and exploring the CIS directory (proc) to inspect buses and USB devices.

Learn how to manage rogue or misbehaving processes with the kill command. Use signals like SIGTERM (15), SIGHUP, SIGINT, SIGQUIT, and SIGKILL to interrupt, quit, or forcefully stop a process.

Use renice to change a running process's priority by its process ID, then restore the task to its original priority after the work completes.

Explore Linux sysctl network settings, including default forwarding and gateway behavior, icmp handling (echo ignore, redirects), ignore broadcasts, and source routing to manage routes and security.

Explore how Linux handles processes and kernel modules, learning to view, kill, and reprioritize processes, and to fine-tune and harden the kernel for performance and control.

Assess the compression ratio to quantify storage savings from a compression algorithm and file type, noting that some files compress poorly.

Explore linux compression utilities, including compress, gzip as the replacement for compress, and formats like gz, zip, and bz2, with gunzip for unzipping.

Explore how gzip, as a replacement for compress, uses options like -d to decompress, -t to test, -v for verbose, -f to force, and compression level flags; learn gunzip.

Use the gui by right-clicking a file, selecting the zip option, and choosing the compression algorithm, avoiding the command line when possible.

Cpio collects and copies files to standard output for backups, while find locates backup targets with cpio using criteria like permissions, name, or last access times, and dump and restore.

Explore dd, a sector-by-sector copy utility used for backups and forensic analysis on hard drives, noting it copies data without performing analysis.

Schedule tasks with the cron command to run on a repeated daily, weekly, or monthly basis by configuring what and when, using crontab and cron.d.

Use iostat to monitor drive input and output and identify bottlenecks, noting that memory swapping can cause high io and slow system performance.

Install systat to run mpstat for cpu usage, i/o wait, and idle time, then use iostat -C and -d to monitor cpu and disk performance and spot bottlenecks.

Examine sar output to analyze cpu utilization, including user, system, io wait, and idle percentages, with repeated runs showing a brief history of each sample.

Explore how the SAR system activity reporter collects CPU and I/O statistics, demonstrates options like -A and -B, and shows defaults and cron scheduling for troubleshooting performance.

Explore memory statistics utilities and process monitoring using uptime, free, vmstat, and top, then use system monitor to view, end, and adjust processes and daemon files.

Learn how load average from the uptime command measures real-time CPU load over 1, 5, and 10 minutes to indicate overload and guide enterprise planning with Apache and MySQL.

Explore Linux log files such as boot, cron, mail, messages, secure, and X window logs to monitor startup, scheduled tasks, backups, and security events.

Explore editing the syslog config to specify facilities and severity levels, targeting log files such as mail, users, and daemons, and define where to store them.

Discover how syslog.conf determines what gets logged on a system, viewing and editing with less and sudo access. Inspect daemon log and facilities by severity levels, and search for errors.

Explore log rotation and its daemon, which keeps log files from getting too large by archiving and rotating them. Configure rotation in the log rotate config and inspect archived files.

Explore a sample logrotate.conf demonstrating how to set rotation frequency, create new log files, apply compression, and store rotation state in /etc/logrotate.d, with separate rules for temp files.

Explore how log rotation archives logs to keep files small, inspect /var/log with less, and review a logrotate setup that rotates weekly, preserves archives, creates empty logs, and avoids compression.

Explain how OSI upper layers map to TCP/IP application and transport, discuss ports and sessions, and describe IPv4/IPv6 addresses and Ethernet MAC addresses.

Compare character based names and static host files with dynamic DNS mappings, and learn how DNS registers name to IP changes as network topology evolves.

Inspect /etc/services with less to view ports, noting tcp/udp usage and common services, most ports are 1–1024, with some outside, and use search engine work to learn meanings.

Explore the triple a of authentication, authorization, and accounting, and learn how remote access relies on authentication, permission control, and logging of actions under accounting.

One-factor authentication is easy to break through social engineering and password exposure; adopt multi-factor authentication using two or more factors: something you know, something you are, or something you have.

Explore network time services and the NTP protocol, which keeps servers and clients synchronized to an authoritative time source to prevent replay attacks and ensure small time differences.

Watch a demo of viewing daemon startup options. Learn how the inetd config on Debian controls services, and how /etc/rc*.d directories list startup services that boot Linux.

Learn to use DNS tools such as nslookup, dig, and host to resolve names, query authoritative name servers, inspect NS records, and perform forward lookups with debian.org.

Manage the bind dns service by starting, stopping, or restarting it to recover from issues, using the init daemon and init.d or rc.d paths.

Examine how the host file resolves names to IPs, guided by the name service switch, using local files and the loopback address before DNS.