Tip1. Checks if a service is running.
systemctl status httpd or systemctl is-active httpd
Tip2. Stops a service.
systemctl stop httpd
Tip3. Starts a service.
systemctl start httpd
Tip4. Restarts a service.
systemctl restart httpd
Tip5. Restarts a service only if it is running.
systemctl try-restart httpd Now stop apache service and try to restart using try-restart. It will not restart. systemctl stop httpd systemctl try-restart httpd systemctl status httpd (Service will be Stopped)
Tip6. Reloads configuration (Main PID will not change on reload)
systemctl reload httpd
Tip7. Displays the status of all services.
systemctl list-units --type service --all
Tip8. Displays the status of running services.
systemctl list-units --type service --all | grep running
Tip9. Enables a service so that on boot it could automatically up
systemctl enable httpd
Tip10. Checks if a service is enabled.
systemctl is-enabled httpd or systemctl status httpd
Tip11. Disables a service so that it could not up automatically at the time of boot.
systemctl disable httpd
Tip12. Lists all services and checks if they are enabled.
systemctl list-unit-files --type service systemctl list-unit-files --type service | grep enabled
Tip13. Lists services that are ordered to start before the specified unit.
systemctl list-dependencies --after network
Tip14. Lists services that are ordered to start after the specified unit.
systemctl list-dependencies --before network
Tip15. If you want to ensure that the symbolic links are re-created, use the following command
systemctl reenable httpd
Tip16. you can mask any service unit to prevent it from being started manually or by another service.
systemctl mask httpd This command replaces the /etc/systemd/system/name.service file with a symbolic link to /dev/null # systemctl restart httpd Failed to restart httpd.service: Unit is masked.
Tip17. To revert this action and unmask a service unit,
systemctl unmask httpd
Tip18. Viewing the Default Target
Tip19. Viewing the Current Target
systemctl list-units --type target systemctl list-units --type target graphical.target systemctl list-units --type target multi-user.target
Tip20. Changing to Rescue Mode
systemctl rescue To prevent systemd from sending this message, run this command with the --no-wall command line option: systemctl --no-wall rescue
Tip21. Changing to Emergency Mode
systemctl emergency To enter emergency mode without sending a message to all users that are currently logged into the system, run the following systemctl --no-wall emergency After work come to default mode systemctl default
Tip22. Restarts the system.
Tip23. Powers off the system.
systemctl poweroff Power off in a specified time. shutdown --poweroff hh:mm
Tip24. Suspends the system. (This command saves the system state in RAM and with the exception of the RAM module)
Tip25. Hibernates the system.
Tip26. CONTROLLING SYSTEMD ON A REMOTE MACHINE
systemctl -H email@example.com status httpd.service In the similar way you can start , stop , status, enable, disable of services on remote host.
For Live Installation you may refer below youtube link:-