Linux Certified System Admin - SA1 (RHEL7)

Download and set up Red Hat Enterprise Linux ISO or CentOS ISO using VMware Workstation or Oracle VirtualBox, noting subscription requirements and 60-day trial availability.

Follow step-by-step instructions to install Red Hat Enterprise Linux 7, from selecting the iso image and booting the installer to configuring language, time zone, keyboard, installation source, and partitioning.

Connect from a Windows laptop to a Linux VM using PuTTY, install the client, configure the VM's IP via DHCP or a static setup, and log in.

Explore the Linux file system hierarchy, including directories for user programs, system administration commands, home directories, bootloader files, system libraries, optional applications, and media mount points.

Explore how absolute paths specify a complete location from the root and how relative paths reference locations from your present working directory.

Explore absolute paths and relative paths on a Linux server, practicing navigation and file access. Learn how to read files using absolute or relative paths and locate destinations efficiently.

Practice session teaches locating files and directories using simple Linux commands like cat, pwd, cd, and ls with -l and -a; create files with touch and switch users with su.

Master file management on the command line by copying, moving, and removing files and directories with cp, mv, and rm, including recursive and forced options.

Learn practical file management in Linux by creating directories and subdirectories, copying directories with contents, moving and removing items, and handling overwrites and destinations.

This lab teaches pattern matching in the linux terminal by creating directories and files with touch, navigating directories, and using wildcards to filter file names.

Learn how to use the man command on Linux and Unix-like systems to view manual pages, navigate sections 1 through 9, and search with man -k for keywords.

Analyze how the pinfo command lets you view info files and manuals, offering a structured alternative to man pages, with navigation using arrows and menus.

Explore package documentation in /usr/share/doc for installed packages. Read manuals, info pages, licensing notes, and examples to configure and use the package effectively.

Discover how to access the Red Hat customer portal with your subscription credentials, search solutions, read FAQs and the knowledge base, and raise and prioritize tickets with a SARS report.

Create and view the SARS report, generate the compressed archive, locate it, and upload the file to the redhead customer portal to raise a ticket.

Learn how to work with standard input, standard output, and standard error in Linux, including file descriptors 0, 1, 2, and redirecting output to a file.

Learn to redirect output to a file or program, directing stdout and standard error, using overwrite, append, and nullify options to control where output goes.

Learn redirecting output in shell scripting by directing standard output and errors to a file, using > to overwrite and >> to append, while preserving existing content.

Edit text-based Linux files with Vim, creating, opening, and saving changes. Use split-screen mode, color highlighting, and visual mode for copy and delete.

Learn to create Linux users and groups, assign primary groups, configure user IDs, home directories, and shells, and examine passwd and shadow entries to implement password aging policies.

Learn to create groups and users on a Linux system, assign a primary or secondary group, and verify ownership and permissions, with admin rights and clean deletion procedures.

Learn what sudo is and why we use it to grant temporary administrative access; explore the sudoers file, permissions, and aliases to manage who can run commands.

Explore how the sudoers file controls who can use sudo to run privileged commands. Learn the syntax, including host, users and groups, and run as, and edit it safely.

Learn how to grant a normal user sudo access, elevate to root from a normal user, and restart services like Apache with no password options, following recommended practices.

Demonstrate Linux password aging and expiry with the chage command, viewing and modifying expiry data, and configuring minimum, maximum days and expiry warnings for users.

View and modify a user's password aging policy, including expiry dates, warning days, and password age limits. Enforce inactivity and account expiration to control login prompts.

Learn how Linux file and directory permissions control who can read, write, or execute, assigned to owner, group, and others to protect against accidental or deliberate damage.

Master linux file permissions by interpreting ls -l output, distinguishing files, directories, and links, and mapping permission bits for owner, group, and others (read, write, execute).

Explore access modes in Linux, including absolute and symbolic permissions. Interpret numeric values like 4 2 1 and examples such as 777, 755, and 600 using long listings.

Master Linux file permissions and ownership with chmod and chown, learning how to modify permissions, set ownership, and manage user and group ownership for files and directories.

Explore Linux file permissions and setuid concepts in lab sessions: see how a setuid binary can change passwords despite restrictive file permissions, and how processes inherit owner permissions from files.

Explore the sticky bit, a special folder permission that lets only the owner or root delete files; learn to apply it with chmod and recognize small d and capital-T indicators.

Understand process management, including what a process is and how the kernel creates one with memory, then view running processes using ps with -x and long listings.

Learn to manage foreground and background processes in Linux, using ampersand to run in the background and track job and process IDs.

Practice lab session 1 teaches Linux system admins process management, including observing process IDs, shells, and teletype and virtual terminals, and adjusting priority with nice values.

Explore practical process management in Linux using ps and top to inspect PID, owner, status, memory, and start time, and learn about parent and child processes and safe termination.

Explore how foreground and background Linux processes operate by running a shell loop, streaming real-time file updates with tail, and managing jobs with ctrl-z, fg, and bg.

Learn how systemd, the init replacement, serves as the service manager, enabling on-demand startup and dependency-based boot to reduce boot time while centralizing logs for easy viewing.

Explain how BIOS selects boot media, loads the kernel via initramdisk, and how systemd starts services through targets like multi-user and graphical, driven by the default target.

Compare RHEL7 and RHEL6, noting XFS as the default file system on RHEL7, runlevels replaced by targets in the new init system, and UID starting at 2000 versus 500.

Practice lab session on using systemctl to check service status, start and stop processes, and enable or disable services, including how enabling creates startup links for the multi-user.target.

Explore analyzing the Linux boot process with systemd tools, measuring boot duration, identifying time per task with blame, and inspecting boot logs with journalctl to troubleshoot.

Discover how SSH enables secure, encrypted remote access to your data center with OpenSSH, using port 22, key-based authentication, and features like port forwarding and encrypted channels.

Learn to configure the openSSH server's sshd_config to manage idle disconnections by setting ClientAliveInterval and ClientAliveCountMax, ensuring users are disconnected after about 10 minutes of inactivity.

Practice lab session demonstrates configuring ssh access on a linux host: back up ssh config, disable root login, use allow and deny rules to control user access, then restart sshd.

Practice lab session on configuring access to a Linux box, opening port 22, and restarting the SSH service, with firewall and Linux security considerations.