systemctl -t help
 
systemctl list-unit-files
 
systemctl list-units
 
systemctl start name.service
 
systemctl stop name.service
 
systemctl status name.service
systemctl status name.service -l
 
systemctl enable name.service
 
systemctl disable name.service
 
systemctl cat name.service
 
systemctl show
 
systemctl edit
 
systemctl daemon-reload
 
systemctl list-dependecies name.target 
 
systemctl start name.target
 
systemctl isolate name.target 
 
systemctl get-default 
 
systemctl set-default name.target 
 
 
multi-user.target
 
graphical.target
 
emergency.target
 
[root@ip-10-0-1-205 system]# cat /etc/systemd/system/target.service 
[Unit] 
Description=Log when default target reached
After=cloud-final.service 
 
[Service] 
Type=oneshot        
RemainAfterExit=yes   
ExecStart=/bin/echo "--->  Reached default.target"
ExecStart=/usr/bin/ls -l /etc/systemd/system/default.target 
 
[Install]  
WantedBy=default.target

Referencias