Linux Plus

Who Should Take This

It is intended for system administrators, DevOps engineers, and IT professionals who have at least twelve months of hands‑on Linux administration experience. These learners aim to validate their skills, deepen knowledge of security hardening, automation, and containerization, and advance their careers by achieving the CompTIA Linux+ credential.

What's Included in AccelaStudy® AI

Adaptive Knowledge Graph

Practice Questions

Lesson Modules

Console Simulator Labs

Exam Tips & Strategy

20 Activity Formats

Course Outline

69 learning goals

1 Domain 1: System Management

6 topics

Boot Process and Initialization

Describe the Linux boot sequence from BIOS/UEFI through bootloader (GRUB2), kernel initialization, initramfs, and systemd target activation.
Configure GRUB2 bootloader settings including default boot entry, timeout, kernel parameters, and password protection of the boot menu.
Identify systemd targets (multi-user, graphical, rescue, emergency) and explain how to change the default target and switch between targets at runtime.

Service and Process Management

Apply systemctl commands to start, stop, restart, enable, disable, and check the status of systemd services and examine unit file configurations.
Apply process management commands (ps, top, htop, kill, killall, nice, renice, nohup) to monitor, prioritize, and terminate running processes.
Configure job scheduling using cron (crontab syntax, /etc/cron.d, anacron) and at commands for one-time and recurring task automation.
Describe the differences between foreground and background processes, job control commands (bg, fg, jobs), and signal types (SIGTERM, SIGKILL, SIGHUP).

Kernel and Hardware Management

Describe the role of the Linux kernel, loadable kernel modules, and apply modprobe, lsmod, and modinfo commands to manage kernel modules.
Apply hardware detection commands (lspci, lsusb, lsblk, dmidecode, dmesg) to identify and verify system hardware components and driver assignments.
Describe the /proc and /sys virtual filesystems and how they expose kernel parameters and hardware information to user space.

Storage Management

Identify Linux filesystem types (ext4, XFS, Btrfs, ZFS) and describe their features including journaling, snapshots, and maximum file/volume sizes.
Apply disk partitioning tools (fdisk, gdisk, parted) to create, modify, and delete MBR and GPT partitions on block devices.
Configure Logical Volume Manager (LVM) to create physical volumes, volume groups, and logical volumes and extend or reduce volumes dynamically.
Configure software RAID arrays (levels 0, 1, 5, 6, 10) using mdadm and describe the performance and redundancy tradeoffs of each level.
Apply mount, fstab, and automount configurations to persistently attach filesystems and configure mount options (noexec, nosuid, ro, quota).
Evaluate storage configurations to determine optimal filesystem type, partition scheme, and volume management strategy for given workload requirements.

Package Management

Identify package management tools for RPM-based (dnf, yum, rpm) and Debian-based (apt, dpkg) distributions and describe repository configuration.
Apply package management commands to install, update, remove, and query packages and resolve dependency conflicts across RPM and DEB systems.

File System Hierarchy and Navigation

Describe the Filesystem Hierarchy Standard (FHS) directories (/bin, /etc, /home, /var, /tmp, /usr, /opt, /dev, /proc, /sys) and their purposes.
Apply file manipulation commands (cp, mv, rm, find, locate, tar, gzip, xz) and I/O redirection (stdin, stdout, stderr, pipes) for file operations.
Apply text processing commands (grep, sed, awk, cut, sort, uniq, wc, diff, head, tail) to extract, transform, and analyze text data from files and command output.

2 Domain 2: Security

6 topics

User and Group Management

Apply useradd, usermod, userdel, groupadd, and groupmod commands to create, modify, and remove user accounts and groups on a Linux system.
Describe the structure and purpose of /etc/passwd, /etc/shadow, /etc/group, and /etc/gshadow files and explain password aging policies (chage).
Configure sudo access by editing /etc/sudoers with visudo to grant granular privilege escalation to specific users and groups.

File Permissions and Access Control

Describe POSIX file permissions (read, write, execute) for owner, group, and other and apply chmod with symbolic and octal notation to set permissions.
Configure special permissions (SUID, SGID, sticky bit) and explain their security implications on files and directories.
Apply POSIX Access Control Lists (ACLs) using setfacl and getfacl to implement fine-grained permission controls beyond standard owner/group/other.
Apply chown and chgrp commands to change file ownership and group membership and configure default permissions using umask.

Mandatory Access Control

Describe SELinux modes (enforcing, permissive, disabled), security contexts (user, role, type, level), and explain the purpose of targeted policy.
Apply SELinux management tools (semanage, restorecon, setsebool, getsebool, audit2allow) to troubleshoot and resolve SELinux denials.
Compare SELinux and AppArmor approaches to mandatory access control and evaluate which framework is appropriate for given distribution and security requirements.

Firewall and Network Security

Identify Linux firewall frameworks (iptables, nftables, firewalld) and describe the relationship between chains, tables, rules, and zones.
Configure firewalld zones and rules to allow, deny, and forward traffic and implement port forwarding and rich rules for complex filtering scenarios.
Configure iptables/nftables rules for input, output, and forward chains to implement stateful packet filtering and network address translation.

SSH and Remote Access Security

Configure SSH server settings (sshd_config) to disable root login, enforce key-based authentication, change default ports, and restrict access by user or group.
Apply SSH key pair generation, distribution, and management using ssh-keygen, ssh-copy-id, and authorized_keys for passwordless authentication.
Configure SSH tunneling (local, remote, dynamic port forwarding) and explain use cases for secure access to remote services through encrypted channels.

PKI, TLS, and Auditing

Describe PKI concepts including certificate authorities, certificate signing requests (CSR), public/private key pairs, and certificate chain validation on Linux.
Apply OpenSSL commands to generate keys, create CSRs, self-sign certificates, and configure TLS for web servers (Apache/Nginx) and mail services.
Configure Linux audit frameworks (auditd, audit rules, ausearch, aureport) to track file access, privilege escalation, and system call events.
Assess Linux system security posture by reviewing authentication logs, audit trails, open ports, and running services to identify hardening opportunities.

3 Domain 3: Scripting, Containers, and Automation

4 topics

Bash Scripting Fundamentals

Describe bash script structure including shebang lines, variable declaration, quoting rules, exit codes, and command substitution syntax.
Implement bash conditional statements (if/elif/else, case, test, [[ ]]) and comparison operators for string, numeric, and file test operations.
Implement bash loops (for, while, until) and functions with parameters, return values, and local variable scope for reusable script components.
Apply input validation, error handling (set -e, trap), and logging techniques to create robust and maintainable automation scripts.

Regular Expressions and Text Processing

Describe basic and extended regular expression syntax including character classes, quantifiers, anchors, grouping, and alternation operators.
Apply regular expressions with grep, sed, and awk to search, filter, transform, and extract structured data from log files and command output.

Container Management

Describe containerization concepts including images, containers, registries, layers, namespaces, and cgroups and compare containers with virtual machines.
Apply Docker or Podman commands to pull images, run containers, map ports and volumes, manage container lifecycle, and inspect container logs.
Implement Dockerfiles to build custom container images with proper layering, multi-stage builds, and security best practices (non-root users, minimal base images).
Evaluate container orchestration approaches and describe the role of Kubernetes pods, deployments, services, and namespaces in managing containerized workloads.

Infrastructure as Code and Automation

Describe infrastructure-as-code concepts including declarative vs. imperative approaches, idempotency, and state management for system provisioning.
Explain the roles of configuration management tools (Ansible, Puppet, Chef, Salt) and differentiate agent-based from agentless architectures.
Analyze automation requirements to recommend appropriate tooling choices between shell scripts, configuration management, and container orchestration approaches.

4 Domain 4: Troubleshooting

5 topics

Log Analysis and Monitoring

Identify standard log file locations (/var/log/messages, /var/log/syslog, /var/log/auth.log, /var/log/secure) and describe the role of rsyslog and systemd-journald.
Apply journalctl commands with filters (unit, priority, time range, boot) to query and analyze systemd journal entries for troubleshooting.
Analyze log entries to identify root causes of service failures, authentication problems, kernel panics, and hardware errors across multiple log sources.

Network Troubleshooting

Apply ip, ss, and nmcli commands to verify network interface configuration, routing tables, active connections, and NetworkManager profiles.
Apply ping, traceroute, dig, and curl commands to diagnose network connectivity, DNS resolution, and HTTP service reachability on Linux systems.
Troubleshoot Linux network configuration issues including incorrect IP assignments, missing default gateways, DNS resolution failures, and firewall rule conflicts.

Storage Troubleshooting

Apply df, du, lsblk, blkid, and smartctl commands to diagnose disk space exhaustion, mount failures, and device identification issues.
Troubleshoot filesystem corruption using fsck, xfs_repair, and filesystem-specific recovery tools and explain when to use each in read-only vs. unmounted scenarios.
Troubleshoot LVM and RAID degradation issues including failed physical volumes, degraded arrays, and volume extension failures using appropriate recovery procedures.

Performance Analysis

Apply performance monitoring tools (top, htop, vmstat, iostat, mpstat, sar) to collect CPU, memory, disk I/O, and system load metrics in real time.
Analyze system performance data to identify CPU bottlenecks, memory pressure (swapping), I/O wait conditions, and resource contention between processes.
Evaluate kernel tuning parameters (sysctl, /proc/sys) and resource limits (ulimit, cgroups) to optimize system performance for specific workload patterns.

Boot and Service Recovery

Troubleshoot boot failures by identifying symptoms at each boot stage (GRUB errors, kernel panics, initramfs failures, systemd dependency failures).
Apply rescue and emergency boot procedures to repair broken configurations including regenerating initramfs, reinstalling GRUB, and resetting root passwords.
Troubleshoot systemd service failures by analyzing unit file dependencies, examining journal output, and identifying circular dependency and resource constraint issues.

Scope

Included Topics

All domains in the CompTIA Linux+ (XK0-006) exam: System Management (32%), Security (21%), Scripting, Containers, and Automation (19%), and Troubleshooting (28%).
Linux boot process, systemd service management, kernel modules, hardware detection, storage management (LVM, RAID, filesystem types), process management, and job scheduling (cron, at).
User and group management, file permissions (POSIX, ACLs, SUID/SGID/sticky bit), mandatory access control (SELinux/AppArmor), firewall configuration (iptables/nftables/firewalld), SSH hardening, PKI/TLS, and system auditing.
Bash scripting fundamentals (variables, loops, conditionals, functions), regular expressions, container management (Docker/Podman), container orchestration basics, and infrastructure-as-code concepts.
Log analysis (journalctl, /var/log), network troubleshooting (ip, ss, nmcli), storage troubleshooting, performance analysis (top, iostat, vmstat, sar), and boot repair (GRUB, initramfs).

Not Covered

Advanced kernel development, kernel compilation from source, and custom kernel module programming beyond basic module management.
Enterprise-scale configuration management tool implementation (Ansible playbook authoring, Puppet manifest development, Chef recipe creation) beyond conceptual understanding.
Cloud-native Kubernetes cluster administration, Helm chart development, and service mesh configuration beyond basic container orchestration awareness.
Distribution-specific package management internals and packaging format creation (RPM spec files, DEB packaging) beyond standard package installation and management.
Advanced network routing protocol configuration and software-defined networking implementation on Linux platforms.