Manage Services in Linux

This virtual hands-on challenge explains how to form ‘systemctl’ commands and use them to manage network services. Learners research and display documentation about the subcommands and correct command syntax. Participants also start, stop, enable, disable, restart, and reload through executing ‘systemctl.’ Learners gain feedback when they execute ‘systemctl’ for an active service versus a dormant one.

This lab runs for 45-minutes and requires time to run the entire challenge from start to finish. Learners cannot pause or come back to a section in the middle. Beginners who have started Terminal in Linux before the lab have the preparation needed to get the most from the IT Pro Challenge lab. Should the learner choose to select the hint link, he or she sees guidance with screenshots and video. Hint links appear at the end of each section and help users check their work.

Linux, upon startup, loads fundamental components, including network services. While performing system updates, troubleshooting, managing, or verifying service performance, System Administrators use the ‘systemctl’ command set. As learners gain direct experience, they see how systemd resources respond. Also, lab participants create and run commands within the terminal application, the background needed for upgrading scripting skills.

Explore the ‘systemctl’ Command and Current Service Configuration:

In this portion, the learner opens Terminal, using root privileges that provide administrative access needed to use the ‘systemctl’ command set. Learners practice correct syntax: ‘systemctl subcmd servicename.’ Users also determine the statuses of a few services running on CentOS 7. At the end of this section, users try out the depreciated commands that managed CentOS 6 services. Participants discover how the older ‘service’ and ‘chkconfig’ commands differ.

Configure the Startup Settings for Services Using the ‘systemctl’ Command:

Lab participants use ‘systemctl’ with appropriate sub-commands to try out starting, stopping, enabling, and disabling network services: ssh, firewall, and HTTP. Learners also verify how well a service function using the status subcommand.

Restart and Reload the sshd Service:

Learners restart and reload a service in CentOS 7. System Administrators need to have this ability on hand in case configuration files contain edits. Restarting and reloading services directs the system to reread the services configuration files. Although the ‘restart’ command drops any network communications and the ‘reload’ maintains any existing network exchanges.

Display a List of ‘systemctl’ Subcommands by Using Tab Completion in Bash:

This section shows the learner how to look for ‘systemctl’ commands on the fly. The screenshot, in the hint, also displays a list of subcommands that could be cut out and pasted on a sticky reminder. By practicing completing systemctl’ command with tab, learners apply tab with other commands. Learners can then list Linux subcommands used with other commands.

Summary:

At the end of the Mange Services in Linux virtual lab, learners obtain important experience with the ‘systemctl’ command, including:

• • Checking service status by using the ‘systemctl,’ ‘ps,’ ‘pstree,’ and ‘service.’
• • Using the ‘systemctl’ to setup startup configurations for services.
• • Handling changes in the service configuration files by restarting or reloading services.
• • Displaying subcommands through the tab completion feature of bash.

Learners looking to advance their Linux skills and expertise should consider other labs.

• • GUIDED CHALLENGE: Configure and Use GUI Administration Tools in Linux

• • ADVANCED CHALLENGE: Can You Configure Firewalld in Linux?