So i have found a script that uses sleep after system d command. As far as I'm concerned, it doesn't run asynchronously so the sleep is not necessary, right?

Adding a piece of code, for better understanding.

systemctl daemon-reload
sleep 10s
systemctl start $service_name
sleep 10s 

CodePudding user response：

Correct. New or updated unit files will be available directly after systemctl daemon-reload has completed.