Linux Commands and System Administration Bootcamp

Download and install VirtualBox on Windows, following the setup wizard and default options. Launch Oracle VM VirtualBox from the desktop to begin.

Learn how to download Santos Linux, select the DVD ISO, install Santos Linux in Oracle VM VirtualBox with a GNOME desktop, and set up root and an administrator user.

Install Red Hat 8 in Oracle VirtualBox with custom partitioning, create a volume group with root, home, var, log, tmp, and swap, then set up GNOME and network.

Download and install Putty from putty.org, select 64-bit or 32-bit, then open the client, enter the server IP, and log in with your user ID and password.

Connect to Linux servers using Oracle VM VirtualBox, PuTTY, and SSH from one server to another, including booting, logging in, and entering passwords.

Explore the Linux directory structure and file system hierarchy, detailing key directories such as /boot, /root, /dev, /ETSI, /bin, /proc, /var, /tmp, /home, /opt, /run, and /media.

Master basic Linux commands like cd, ls, cat, and pwd to navigate directories, view files, and access help via man pages in the terminal.

List directory contents with ls, inspect details using ls -l, reveal hidden files with ls -a, and identify file types via -F and the file command.

Learn how to change your own password and reset other users' passwords using the passwd command, with root privileges, while understanding system security policies and password requirements.

Explore how to locate files in Linux using the find command, searching by name, size, location, and time, with options like print and delete, and consult the man pages.

Learn to create, edit, and save files with the vi editor (vim) on Linux, navigate command, insert, and line modes, and perform copy, paste, undo, search, and substitute operations.

Copy files and directories with the cp command, noting that existing files are overwritten by default; add -i for confirmation and -R to copy directories recursively.

Learn to remove files and directories using rm, with -i for confirmation and -f for force, and use rm -r or rm -rf to delete non-empty directories recursively.

Master moving and renaming files and directories with mv, including the -i option to avoid overwriting, with examples renaming file one to file two and dir one to dir two.

Explain absolute versus relative paths, show how absolute paths start with a slash and relative paths rely on your current directory, and demonstrate navigation with dot, dot-dot, tilde, and cd.

Learn to create files and directories using the touch command, vi editor, and the make dir command, including multiple files, verifying with ls, and nested directories with -p.

Understand how to assign read, write, and execute permissions to users, groups, others, and all for files and directories, and how ls -l reveals these rights.

Learn how to change file permissions using symbolic and octal notation with chmod, including user, group, and others, plus examples and cautions against 777 or 666.

Modify file ownership and group ownership using chown and chgrp, including setting both owner and group in one command, and apply changes recursively to directories with -R.

Navigate large files using more and less to view content page by page or line by line, start from a specific line, and search with slash or grep via pipes.

Learn head and tail basics to view default first or last ten lines, adjust by specifying a number of lines, and monitor logs in real time with tail minus F.

Master tab completion in the bash shell to quickly complete files, directories, and commands. Use a single tab to auto-complete and double tab to display all possibilities.

Learn how bash stores command history in a home directory file, view history with paging, and re-run commands using exclamation, bang, or the up arrow.

Master wild cards for pattern matching in Linux commands such as ls and cp, using asterisk, question mark, and square brackets with examples.

Explore soft and hard links in Linux, learn how inodes store file metadata and identifiers, and compare how hard links share an inode while soft links point to another file.

Learn to redirect input, output, and errors in Linux commands, using input redirection, output redirection (overwrite or append), and redirecting errors or both to files or /dev/null.

Learn how to use grep to search plain text for lines matching a regular expression and print out results, including options to exclude matches, search case-insensitively, and number matching lines.

Discover how the pipe command enables piping data by sending the output of one command as input to another, using grep, less, head, and tail to refine results.

Learn how to create and use shell aliases to shorten commands, view and test them in bash, and make aliases permanent by editing the bashrc file.

Explore the echo command in Linux, a built-in tool that displays text or variables passed as arguments to the screen or a file, especially in shell scripts.

Explore environment variables, their role in the shell, and how to define, export, and unset them, including local versus environment scope and prompt customization with PS1.

Connect to another server with ssh using an IP or hostname, log in with your password, then exit; if you use the same username, you can omit it.

Learn secure file transfer across servers using scp and sftp, copying files to and from /tmp, authenticating over ssh, and using put and get commands to manage transfers.

Learn to count lines, words, and characters or bytes with the wc command. Explore -l, -w, -c, and -m options and apply them to example files.

Learn to view and monitor Linux processes with ps and top, interpret PID, user, CPU time, memory, and status, and use options like -a -e -f -F to troubleshoot /proc.

Schedule and automate tasks with cron and cron tab to run commands or scripts at set times. Manage cron jobs with comments and the five-asterisks timing format, including backups.

Master user and group administration with commands like user add, user del, group add, group del, and user mod; create, delete, and modify accounts and groups.

Switch users from the command line using su and su -, compare root and regular sessions, and note password prompts and environment changes.

Explore how to grant sudo privileges to users and groups, edit the sudoers file to specify allowed commands and no password access, and verify rights with sudo -l.

Learn to compress and archive files and directories using gzip, gunzip, bzip2, and tar, including creating, listing, extracting tarballs, and combining archiving with gzip compression.

Discover how to display and set the host name using host name and hostnamectl, and learn how reboots or editing the hostname file make changes permanent across the system.

Find your ip on Linux using hostname -I to display all interface addresses. The ip addr command shows more details, like interface names and the loopback address, across different distros.

Translate text with tr, sort files by order, and compare differences with diff in side-by-side and numbered formats. Identify duplicates and refine files using uniq, including repeat detection.

Learn to extract fields with the cut command using a delimiter and field numbers, then sort results in alphabetical, numerical, or reverse order, demonstrated with tail and pipe examples.

Explore 32-bit vs 64-bit operating systems, compare memory limits, performance, and backwards compatibility, and learn to check architecture with arch and uname -m to choose 64-bit systems.

Discover how to gather system information with uname and dmidecode, using options to reveal kernel name, host, release, version, architecture, and BIOS details; includes os release and manual usage.

Learn how to recover a forgotten root password by editing grub to boot into single-user mode, reset the root password with passwd, and relabel the system for Linux.

Learn to use sosreport for Red Hat troubleshooting by installing sos, generating a report, and uploading the compressed file to Red Hat support with a case ID.

Learn to monitor system users using commands like id, who, last, and w; view user IDs, group IDs, active logins, and boot and run level history for troubleshooting.

Learn how to use motd and wall to communicate with logged-in users, display company policies at login, and broadcast real-time reboot notices across the system.

Learn to manage software with yum on Red Hat family systems, installing, updating, and removing packages, resolving dependencies, handling repositories, and using package groups, search, download, info, and history commands.

Explore rpm package management on Red Hat family systems, including installing, upgrading, removing, querying, verifying packages, and locating files, plus how rpm handles dependencies versus yum or zypper.

Explore repositories, or repos, and how yum uses them to install software on CentOS and similar distros. Learn how enabled flags, base URL, mirrors, and gpg checks control installations.

Learn to create a local yum repository by mounting a cd or dvd, copying packages to /repo, and installing software from the local repo.

Learn to prepare Linux system updates with options like yum update versus yum upgrade, use version lock to protect specific packages, and enable repository protection to manage security updates.

Learn to roll back patches and updates in Linux using snapshots and backups. Use yum downgrade and yum history undo, and note when a minor release rollback is appropriate.

Learn to manage software on SUSE Linux with zypper, installing, removing, updating, and applying patches to packages, checking status, and searching installed packages with reboot guidance.

Install and manage deb packages on ubuntu using apt get, practice search, install, remove, update, upgrade, and dist upgrade commands for system administration.

Learn to check the running kernel with uname -r. Update the kernel using yum and verify installations with rpm -qa and yum list, noting CentOS mirrors and grub behavior.

Master adding, deleting, and modifying users and groups using commands such as user add, user del, group add, group del, and user mod, with verification via id.

Create a user account with no login access by assigning a no-login shell (using useradd -s), verify the shell in /etc/passwd, and confirm login is denied.

Learn how to use the passwd command to change your own password, how root or sudo users can change others' passwords, and how to lock, unlock, and set expiry.

Learn to manage password aging on user accounts by viewing settings with change -l and adjusting min, max, and warning days with -n, -x, and -w.

Learn to create, modify, and delete linux group accounts, using groupadd -g 5000 for Linux atm, groupmod to rename and set 6000, and groupdel to remove mgmt with /etc/group verification.

Activate and deactivate the shadow password mechanism to manage shadow files for storing user and group passwords, including password aging attributes and root-only read permissions.

Learn about the three Linux account types (root, normal, service) and how /etc/passwd, /etc/shadow, /etc/group, and /etc/gshadow manage and back up user credentials for login.

Explore the passwd file structure and its seven colon-separated fields used for user accounts. See root’s uid is zero, passwords appear as X in shadow, with home and shell.

Explore the shadow file and shadow password mechanism that secure local passwords. Learn how /etc/shadow stores encrypted passwords and enforces password expiration and per-user limits via nine fields.

Learn how the linux group file stores each group entry, how default user private groups with the same name as users are created, and how group IDs start at 1000.

Explore how the gshadow file secures group passwords by storing encrypted entries readable only by root. Learn the four colon-separated fields: group name, password (or exclamations), group admin, and users.

Learn how to switch users in Linux, why logging in as root is discouraged, and how to use su and su - to run commands as other users.

Learn how to grant and manage privileged access with the sudo utility, edit the sudoers file, set no-password and restricted commands, verify rights, and switch users to perform admin tasks.

Explore how Linux partitions boot, root, and home form the file system, and compare MBR and GPT while using parted, G disk, fdisk, and LVM.

Learn how the logical volume manager provides abstraction between physical storage and the file system, enabling online resizing and spanning disks with physical volumes, a volume group, and logical volumes.

Add a disk to a virtual machine in Oracle VirtualBox via storage settings, create a VDI disk (dynamically allocated by default), choose size, and power off the server.

Learn how to manage storage with parted, create MBR or GPT partition schemes, make and delete partitions, and verify changes on a Linux system.

Create and configure a physical volume, volume group, and logical volume, format with a file system, mount it, and enable automatic mounting via /etc/fstab.

learn how to extend a volume group and its logical volumes by creating a physical volume, extending the vg, and resizing the filesystem on a live system.

Create a mirrored logical volume across two disks, with a volume group. Format as ext4 and mount it for persistent storage.

Move a logical volume's data to a new disk by extending the VG, using PV move, then remove the old PV and verify the VG reflects updated storage.

Remove a logical volume, then a volume group, and finally a physical volume, using the lvremove, vgremove, and pvremove workflows, while verifying with lvs, vgs, and pvs commands.

Explore core network components, including IP addresses, IPv4 and IPv6, subnet masks, and gateways. Compare static IP and DHCP, and examine Ethernet interfaces, virtual interfaces, and MAC addresses.

Describe how IP addresses use four octets with network and host portions, and cover class A, B, and C ranges (1–126, 128–191, 192–223) and their default subnet masks.

Explore TCP and UDP protocols on the transport layer of the OSI model, comparing connection-oriented reliability with guaranteed data delivery and fire and forget speed, including the three way handshake.

Explore the OSI model's seven layers—from application to physical—and how each layer handles data formatting, network communication, and transmission with practical examples.

Use the ping command to test IP connectivity by sending 64-byte ICMP packets, view round-trip time and packet loss, and stop with Ctrl+C.

Explore network interfaces, configuration files and commands for linux administration, including NICs, bonding and teaming for redundancy, IPv4/IPv6, DNS, hosts and resolv.conf, with NetworkManager tools.

Learn to find your ip address using hostname -I to show your ip addresses, and use ip addr to see interfaces and the loopback address across distros.

Power off the server, then add and enable a second network adapter in Oracle VM VirtualBox Manager, set to a bridged adapter with promiscuous mode set to allow all.

Configure nic bonding with network manager by adding two interfaces, loading the bonding driver, creating bond zero in round robin mode, and assigning the ip address 192.168.1.120.

Configure linux firewalls with iptables or firewalld on Red Hat seven, manage services via systemctl, and save rules while opening ports such as 443.

Learn essential Linux server security practices, including physical security, regular updates, least privilege, encryption, secure protocols, firewall and partitions, SSH hardening, auditing, and backups.

Learn to install and start a basic Apache httpd web server, configure httpd.conf, create an index.html, and verify the site using the elinks browser on localhost.

Learn to install and configure a lamp stack on Linux by setting up Apache httpd, MySQL or MariaDB, and PHP, enabling services, and verifying versions.