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