systemctl - Control the systemd system and service manager
syntax $ systemctl [OPTION] [SERVICE]
To start service $ sudo systemctl start mariadb.service $ sudo systemctl start sshd
To stop service $ sudo systemctl stop mariadb.service $ sudo systemctl stop sshd
To restart or reload service $ sudo systemctl reload mariadb.service $ sudo systemctl restart mariadb.service
To reload a service default, but if reload is not available for that service. It will restart it $ sudo systemctl reload-or-restart mariadb.service
To check status of service $ sudo systemctl status mariadb.service $ sudo systemctl status sshd
To enable service $ sudo systemctl enable mariadb.service $ sudo systemctl enable sshd
To disable service $ sudo systemctl disable mariadb.service $ sudo systemctl disable sshd
To check Service is enabled or disabled $ sudo systemctl is-active mariadb.service $ sudo systemctl is-active sshd $ sudo systemctl is-enabled mariadb.service $ sudo systemctl is-enabled sshd
To see the status of all services $ sudo systemctl list-units --type=service
To List services by status $ sudo systemctl list-units --type=service --state=active $ systemctl list-units --type=service --state=running $ systemctl list-units --type=service --state=stopped $ systemctl list-units --type=service --state=enabled $ systemctl list-units --type=service --state=disabled $ systemctl list-units --type=service --state=failed
To prevent service from starting $ sudo systemctl mask {servicename}
To Kill a service with signal 15 $ sudo systemctl kill {servicename}
To Kill a service with signal 9 $ sudo systemctl kill -s 9 {servicename}
To Reboot $ sudo systemctl reboot
To shutdown $ sudo systemctl poweroff
To change default to GUI $ sudo systemctl set-default graphical.target
To switch to multi-user.target $ sudo systemctl isolate multi-user.target
To reload daemon $ systemctl daemon-reload
To find version $ systemctl --version
regards, T.Dhanasekar