RHCSA Objective: Operate running systems

This lab exercise uses the Alpha Lab we have setup. The point of this lab exercise is to cover the requirements of the RHCSA objective Operate running systems.

Useful documentation

List of objectives

Boot, reboot, and shut down a system normally

  • systemctl poweroff
  • systemctl reboot

Extra information: https://askubuntu.com/questions/64995/what-is-the-difference-between-shutdown-and-poweroff-commands

Boot systems into different targets manually
Interrupt the boot process in order to gain access to a system
Identify CPU/memory intensive processes, adjust process priority with renice, and kill processes
Locate and interpret system log files and journals

  • journalctl

Access a virtual machine’s console
Start and stop virtual machines
Start, stop, and check the status of network services

  • systemctl -at service
    Show all configured services
  • systemctl start name.service
    Start a service
  • systemctl stop name.service
    Stop a service
  • systemctl restart name.service
    Restart a service
  • systemctl enable name.service
  • systemctl disable name.service
    Enable / disable a service

Securely transfer files between systems

Linux Lab Setup: ‘Alpha Lab’

This post documents the setup of our Linux lab ‘Alpha Lab’. This lab is a basic setup that focusses on basic Linux system administration.

I have used CentOs version 7 (CentOS-7-x86_64-Minimal-1611.iso) for this lab and the lab exercises but use the term RHEL7 to indicate the Linux version.

VM: E7-Router

  • Standard RHEL7 virtual machine
  • Two NICS
    • enp0s3: NAT connection ‘to the internet’
    • enp0s8: Internal network
  • During installation:
    • Configure enp0s3 for DHCP
    • Configure enp0s8 with a static IP 192.168.99.254/24
    • Don’t select other packages
    • Default filesystem / partition layout
    • Set timezone and configure NTP
  • After installation, update all packages, install vim and tmux (my personal preference, substitute as desired)
    • yum update -y
    • yum install -y vim-enhanced tmux
  • Create a snapshot called ‘Clean slate’ for easy rollback

VM: E7-Server1

  • Standard RHEL7 virtual machine
  • One NIC
    • enp0s3: Internal network