Managing Key Services on RHEL 8 - systemd/Scheduling/Time Services

30 minutes
  • 4 Learning Objectives

About this Hands-on Lab

An important part of Linux system administration is managing scheduled tasks. Scheduled tasks can be used for system management, applications, reporting and more. In this hands-on lab, we will examine scheduling tasks using at and cron. Additionally, a key part of managing a RHEL 8 system is managing services using ‘systemd’. With ‘systemd’ we can not only configure and manage services, but set and change system boot targets. In these tasks, we will not only start, stop and configure services to start automatically at boot, but will also configure systems to boot into a specific target automatically. Correct system time is critical for a properly functioning server. Important functions like authentication, logging and more depend on the system time being in sync. Finally, we will also examine how to configure time service clients on RHEL 8.

Learning Objectives

Successfully complete this lab by achieving the following learning objectives:

Schedule Tasks Using at and cron
  1. Query and install needed packages.
  2. Configure at tasks and troubleshoot issues.
  3. Configure cron tasks to execute a script on a schedule.
  4. Troubleshoot any issues that occur.
  5. Verify the script performs properly.
Start and Stop Services and Configure Services to Start Automatically at Boot
  1. Query status and troubleshoot a system service
  2. Configure it to start at boot and run persistently
  3. Verify the status of the service.
Configure Systems to Boot into a Specific Target Automatically
  1. Query the system’s default target.
  2. Set a different default target.
  3. Reboot the system to test the configuration.
  4. Verify the default target’s state.
Configure Time Service Clients
  1. Query the status of time services.
  2. Query the current configuration of time sources.
  3. Replace the time sources with your organizational ones.
  4. Verify and get statistics about time services.

Additional Resources

In this lab, you're a sysadmin who needs to understand the various scheduling options for getting tasks done in an automated fashion. This includes one-off's that come up and must be done within a certain amount of time, or those tasks that must happen every day or time cycle no matter what, even if the system reboots in the meantime.

You'll also look into how to ensure that system services are consistently available, or persistent across system reboots, crashes or other system events. As an adjunct to this, you'll want to be certain that your systems boot into a particular systemd target, depending on their function, either text-based or graphical.

Lastly, you'll be working in the future with databases and other time-sensitive services, so you'll be configuring your local client to query and maintain it's system time from authoritative sources.

Red Hat Exam Requirements Covered:

  • Schedule tasks using at and cron.
  • Start and stop services and configure services to start automatically at boot.
  • Configure systems to boot into a specific target automatically.
  • Configure time service clients.

What are Hands-on Labs

Hands-on Labs are real environments created by industry experts to help you learn. These environments help you gain knowledge and experience, practice without compromising your system, test without risk, destroy without fear, and let you learn from your mistakes. Hands-on Labs: practice your skills before delivering in the real world.

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