Notes on Linux Master Level 2 Exam Topics

Key Concepts of the Linux Master Level 2 Exam

Linux Commands and Configurations

  • RAID: Redundant Array of Independent Disks, a technology that combines multiple disks into a single unit.

    • Types:
    • Striping (RAID 0): Data is split across multiple disks; improves speed but not redundancy.
    • Mirroring (RAID 1): Data is duplicated on two or more disks; offers redundancy.
    • Parity: Uses parity data to provide fault tolerance in RAID setups.
    • Example: A RAID 5 setup uses both striping and parity.

  • LVM: Logical Volume Manager, helps manage disk space flexibility.

    • Components:
    • Physical Volume (PV): Original disks or partitions.
    • Volume Group (VG): Collection of PVs.
    • Logical Volume (LV): The equivalent of a partition made from a VG.
    • First component to create: Physical Volume (PV).
Printer and Scanner Commands
  • Printer Commands:
    • lp: Used to send files to the printer.
    • lpstat: Lists the status of print jobs.
  • Scanner Program: SANE (Scanner Access Now Easy) - a toolkit for scanner interface.
Package Management
  • Debian Package Management:
    • Removing vsftpd: Use apt-get purge vsftpd to remove the package and its configuration.
  • RPM Commands:
    • To remove a package without dependencies: rpm -e nmap --nodeps.
File and Process Management
  • File Inspection:
    • To view contents: tar -tvf is often used for tar files.
  • Process Management Commands:
    • kill %2: Terminates background process number 2.
    • ps: Displays processes running on the system.
User Interfaces and Editing
  • vi Editor: Has commands for file manipulation and editing.
    • Command Mode: :w saves changes, :q quits.
    • Specific commands to substitute text, like appending a period to lines ending with 'linux': :%s/linux$/linux./.
  • Emacs: Developed by Richard Stallman, a text editor with powerful features.
Cron Jobs
  • To set up scheduled tasks:
    • Format: 1 1 * * 1 runs a script every Monday at 1:01 AM.
Networking
  • Network Commands:
    • ifconfig: Displays network interface configurations.
    • netstat: Displays network connections.
    • Check the gateway address: Use route command.
Security and Permissions
  • File Permissions:
    • Umask value of 0022 results in default permissions of -rw-r--r-- for new files.
  • Changing Ownership:
    • Command: chown username:group file to change file owner and group.
Virtualization and Clustering
  • Virtualization Technologies:
    • Xen, KVM: Supports paravirtualization.
  • Clustering Solutions: Appropriate technology varies by objective (e.g., high-availability vs. compute-intensive tasks).
Shell Variables and Environment
  • Common Shell Commands:
    • printenv: Displays all environment variables.
    • To change the shell: Use chsh command.
    • To view the current shell, run echo $SHELL.
X Windows System
  • X Windows Opening: Setting up to start X on boot:
    • Configuration changes include setting default to graphical mode.
Miscellaneous
  • Image Viewer: Example programs include totem, GIMP, Eog.
  • Account Management and Authentication: Understand user roles and permissions across different Linux systems.