RedHat Linux System Administration

Objective: Understand Linux history, RedHat ecosystem, and perform RHEL installation.

Topics Covered:

• History of Linux and Open Source
• RedHat Enterprise Linux (RHEL) overview and versions
• RHEL installation methods (DVD, USB, Network, Kickstart)
• System requirements and partitioning schemes
• Initial system configuration and first boot
• Accessing the system (console, SSH)

Tools: VirtualBox/VMware, RHEL ISO, Kickstart files

Objective: Master essential Linux command line operations and navigation.

Topics Covered:

• Linux file system hierarchy (FHS)
• Basic commands: ls, cd, pwd, cp, mv, rm, mkdir, rmdir
• File viewing commands: cat, less, more, head, tail
• Working with links: hard links vs. symbolic links
• Command line shortcuts and history
• Getting help: man pages, info, --help

Tools: Bash shell, command line

Objective: Understand and manage Linux file systems and storage.

Topics Covered:

• File system types: ext4, XFS, Btrfs
• Partitioning tools: fdisk, gdisk, parted
• Creating and mounting file systems
• Logical Volume Manager (LVM) concepts and management
• File system maintenance and repair (fsck, xfs_repair)
• Managing disk quotas

Tools: fdisk, mkfs, mount, lvm commands, df, du

Objective: Manage users, groups, and implement security policies.

Topics Covered:

• User account management: useradd, usermod, userdel
• Group management: groupadd, groupmod, groupdel
• Password policies and aging (chage)
• User profiles and environment files (/etc/profile, .bashrc)
• Switching users (su, sudo) and sudoers configuration
• User and group related files (/etc/passwd, /etc/shadow, /etc/group)

Tools: useradd, groupadd, sudo, visudo, chage

Objective: Master Linux file permissions and advanced access control.

Topics Covered:

• Standard permissions: read, write, execute (chmod, chown, chgrp)
• Special permissions: SUID, SGID, Sticky Bit
• Access Control Lists (ACL) with setfacl and getfacl
• Umask and default permissions
• File attributes (chattr, lsattr)
• Security best practices for file permissions

Tools: chmod, chown, setfacl, getfacl, chattr

Objective: Manage software packages and repositories on RHEL systems.

Topics Covered:

• RPM package management (rpm command)
• YUM vs. DNF package managers
• Configuring and managing repositories
• Installing, updating, and removing packages
• Package groups and modules
• Handling dependencies and transaction history
• AppStream and BaseOS repositories

Tools: rpm, yum, dnf, repoquery

Objective: Manage system services and processes using systemd.

Topics Covered:

• systemd architecture and unit files
• Managing services: systemctl start, stop, enable, disable
• Viewing and controlling processes (ps, top, htop, kill)
• Process priorities (nice, renice)
• Job scheduling with cron and anacron
• System logging with journald and rsyslog
• Boot process and troubleshooting

Tools: systemctl, ps, top, crontab, journalctl

Objective: Configure and troubleshoot network settings on RHEL.

Topics Covered:

• Network interface configuration (nmcli, nmtui, NetworkManager)
• IP addressing and subnetting
• DNS configuration (/etc/resolv.conf)
• Routing and gateway configuration
• Network diagnostic tools: ping, traceroute, netstat, ss, tcpdump
• Configuring hostname and /etc/hosts
• Network bonding and teaming

Tools: nmcli, nmtui, ip, ping, traceroute, ss

Objective: Implement mandatory access control and firewall security.

Topics Covered:

• SELinux concepts: enforcing, permissive, disabled modes
• SELinux contexts and policy management
• Managing SELinux booleans and file contexts
• Analyzing and troubleshooting SELinux denials (audit2why, sealert)
• Firewalld zones, services, and rich rules
• Configuring port forwarding and masquerading
• Managing iptables/nftables as an alternative

Tools: getenforce, setenforce, semanage, firewall-cmd, audit2allow

Objective: Automate system administration tasks with Bash scripting.

Topics Covered:

• Bash scripting basics: shebang, variables, comments
• Conditional statements (if, case)
• Loops (for, while, until)
• Functions and script arguments
• Input/output redirection and pipes
• Automating backups and system maintenance
• Scheduling scripts with cron and systemd timers

Tools: Bash, Vim/Nano, crontab, systemd timers

Objective: Master advanced storage technologies on RHEL.

Topics Covered:

• Advanced LVM features: snapshots, thin provisioning, resizing
• RAID configuration with mdadm (software RAID)
• iSCSI storage configuration (target and initiator)
• Stratis local storage management
• VDO (Virtual Data Optimizer) for compression and deduplication
• Mounting network storage: NFS, Samba/CIFS
• Automount with autofs

Tools: lvm commands, mdadm, iscsiadm, stratis, vdo

Objective: Prepare for RHCSA certification and master troubleshooting skills.

Topics Covered:

• RHCSA exam objectives review
• Practice labs and mock exams
• Boot troubleshooting (GRUB2, rescue mode, emergency mode)
• System recovery techniques
• Performance monitoring and tuning
• Log analysis for problem diagnosis
• Backup and restore strategies
• Exam tips and best practices

Tools: Rescue mode, GRUB2, system logs, performance tools