CompTIA Linux+ XK0-005 Exam Cram

At the impressionable age of 14, William “Bo” Rothwell crossed paths with a TRS-80 Micro Computer System (affectionately known as a “Trash 80”). Soon after the adults responsible for Bo made the mistake of leaving him alone with the TSR-80, he dismantled it and held his first computer class, showing his friends what made this “computer thing” work.  Since that experience, Bo's passion for understanding how computers work and sharing this knowledge with others has resulted in a rewarding career in IT training. His experience includes Linux, Unix, IT security, DevOps, cloud technologies, and programming languages such as Perl, Python, Tcl, and BASH. He is the founder and lead instructor of One Course Source, an IT training organization.

• Introduction. . . . . . . . . . . . xxiv  Part I: System ManagementCHAPTER 1: Linux Fundamentals. . . . . . . . . . . 1Filesystem Hierarchy Standard (FHS).. . . . . . . 1Basic Boot Process.. . . . . . . . . . 3Kernel Panic. . . . . . . . . . . 10Device Types in /dev.. . . . . . . . . 10Basic Package Compilation from Source.. . . . . . 13./configure.. . . . . . . . . . 13make.. . . . . . . . . . . 15make install.. . . . . . . . . . 16Storage Concepts.. . . . . . . . . . 16Listing Hardware Information.. . . . . . . . 22  CHAPTER 2: Manage Files and Directories.. . . . . . . . . 27File Editing.. . . . . . . . . . . 27File Compression, Archiving, and Backup. . . . . . 36File Metadata.. . . . . . . . . . . 41Soft and Hard Links.. . . . . . . . . 43Copying Files Between Systems.. . . . . . . 46File and Directory Operations.. . . . . . . . 49  CHAPTER 3: Configure and Manage Storage Using the Appropriate Tools.. . . 57Disk Partitioning.. . . . . . . . . . 57Mounting Local and Remote Devices.. . . . . . 61Filesystem Management. . . . . . . . . 66Monitoring Storage Space and Disk Usage. . . . . . 70Creating and Modifying Volumes Using Logical Volume Manager (LVM).. . . . . . . . . . 71Inspecting RAID Implementations.. . . . . . . 75Storage Area Network (SAN)/Network-Attached Storage (NAS). . 78Storage Hardware.. . . . . . . . . . 82  CHAPTER 4: Configure and Use the Appropriate Processes and Services.. . . 85System Services. . . . . . . . . . 85Scheduling Services. . . . . . . . . . 90Process Management. . . . . . . . . 97  CHAPTER 5: Use the Appropriate Networking Tools or Configuration Files. . . 113Interface Management.. . . . . . . . . 113Name Resolution.. . . . . . . . . . 122Network Monitoring.. . . . . . . . . 127Remote Networking Tools.. . . . . . . . 132  CHAPTER 6: Build and Install Software. . . . . . . . . 139Package Management.. . . . . . . . . 139Sandboxed Applications.. . . . . . . . . 149System Updates.. . . . . . . . . . 150  Part II: SecurityCHAPTER 7: Manage Software Configurations.. . . . . . . . 155Updating Configuration Files.. . . . . . . . 155Configure Kernel Options.. . . . . . . . 158Configure Common System Services.. . . . . . . 165Localization.. . . . . . . . . . . 172  CHAPTER 8: Security Best Practices in a Linux Environment.. . . . . 177Managing Public Key Infrastructure (PKI) Certificates.. . . 177Certificate Use Cases. . . . . . . . . 181Authentication.. . . . . . . . . . 181Linux Hardening.. . . . . . . . . . 188  CHAPTER 9: Implement Identity Management. . . . . . . . 201Account Creation and Deletion. . . . . . . . 201.bashrc. . . . . . . . . . . 212Account Management.. . . . . . . . . 212  CHAPTER 10: Implement and Configure Firewalls.. . . . . . . . 219Firewall Use Cases.. . . . . . . . . . 219Common Firewall Technologies.. . . . . . . 221Key Firewall Features.. . . . . . . . . 223  CHAPTER 11: Configure and Execute Remote Connectivity for System Management.. 227SSH.. . . . . . . . . . . . 227Executing Commands as Another User.. . . . . . 235  CHAPTER 12: Apply the Appropriate Access Controls. . . . . . . 241File Permissions.. . . . . . . . . . 241Security-Enhanced Linux (SELinux).. . . . . . . 243AppArmor.. . . . . . . . . . . 247Command-Line Utilities.. . . . . . . . . 250  Part III: Scripting, Containers, and AutomationCHAPTER 13: Create Simple Shell Scripts to Automate Common Tasks. . . . 265Shell Script Elements.. . . . . . . . . 265Common Script Utilities.. . . . . . . . . 286Environment Variables. . . . . . . . . 298Relative and Absolute Paths.. . . . . . . . 302  CHAPTER 14: Perform Basic Container Operations. . . . . . . 305Container Management.. . . . . . . . . 305Container Image Operations.. . . . . . . . 312  CHAPTER 15: Perform Basic Version Control Using Git.. . . . . . . 317Introduction to Version Control and Git.. . . . . . 317clone.. . . . . . . . . . . . 321push.. . . . . . . . . . . . 323pull.. . . . . . . . . . . . 324commit.. . . . . . . . . . . . 324add.. . . . . . . . . . . . 325branch/checkout.. . . . . . . . . . 325tag.. . . . . . . . . . . . 329gitignore.. . . . . . . . . . . 330  CHAPTER 16: Common Infrastructure as Code Technologies.. . . . . 333File Formats. . . . . . . . . . . 334Utilities.. . . . . . . . . . . . 335Continuous Integration/Continuous Deployment (CI/CD).. . . 338Advanced Git Topics.. . . . . . . . . 339  CHAPTER 17: Container, Cloud, and Orchestration Concepts.. . . . . 343Kubernetes Benefits and Application Use Cases.. . . . . 344Single-Node, Multicontainer Use Cases. . . . . . 346Container Persistent Storage.. . . . . . . . 346Container Networks.. . . . . . . . . 347Service Mesh.. . . . . . . . . . . 349Bootstrapping. . . . . . . . . . . 350Container Registries.. . . . . . . . . 350  Part IV: TroubleshootingCHAPTER 18: Analyze and Troubleshoot Storage Issues.. . . . . . 353High Latency.. . . . . . . . . . . 353Input/Output Operations per Second (IOPS) Scenarios.. . . 354Capacity Issues.. . . . . . . . . . 355Filesystem Issues. . . . . . . . . . 358I/O Scheduler. . . . . . . . . . . 359Device Issues.. . . . . . . . . . . 360Mount Option Problems.. . . . . . . . . 363  CHAPTER 19: Analyze and Troubleshoot Network Resource Issues.. . . . 365Network Configuration Issues.. . . . . . . . 365Firewall Issues.. . . . . . . . . . 367Interface Errors.. . . . . . . . . . 367Bandwidth Limitations. . . . . . . . . 373Name Resolution Issues. . . . . . . . . 374Testing Remote Systems.. . . . . . . . . 375  CHAPTER 20: Analyze and Troubleshoot Central Processing Unit (CPU) and Memory Issues. . . . 379Runaway Processes.. . . . . . . . . . 379Zombie Processes.. . . . . . . . . . 380High Load Average.. . . . . . . . . . 383High Run Queues.. . . . . . . . . . 384CPU Times.. . . . . . . . . . . 384CPU Process Priorities.. . . . . . . . . 384Memory Exhaustion.. . . . . . . . . 385Out of Memory (OOM). . . . . . . . . 385Swapping.. . . . . . . . . . . 386Hardware. . . . . . . . . . . 388  CHAPTER 21: Analyze and Troubleshoot User Access and File Permissions. . . 397User Login Issues.. . . . . . . . . . 397User File Access Issues. . . . . . . . . 400Password Issues. . . . . . . . . . 404Privilege Elevation.. . . . . . . . . . 405Quota Issues. . . . . . . . . . . 405  CHAPTER 22: Use systemd to Diagnose and Resolve Common Problems with a Linux System. . . . . 411Unit Files. . . . . . . . . . . 412Common Problems.. . . . . . . . . . 429  9780137898558, TOC, 8/11/2022