##########################
## Service Management using systemd and systemctl
##########################
# showing info about the boot process
systemd-analyze
systemd-analyze blame

# listing all active units systemd knows about
systemctl list-units
systemctl list-units | grep ssh

# checking the status of a service
sudo systemctl status nginx.service

# stopping a service
sudo systemctl stop nginx

# starting a service
sudo systemctl start nginx

# restarting a service
sudo systemctl restart nginx

# reloading the configuration of a service
sudo systemctl reload nginx
sudo systemctl reload-or-restart nginx

# enabling to start at boot time
sudo systemctl enable nginx

# disabling at boot time
sudo systemctl disable nginx

# checking if it starts automatically at boot time
sudo systemctl is-enabled nginx

# masking a service (stopping and disabling it)
sudo systemctl mask nginx

# unmasking a service
sudo systemctl unmask nginx