Restarting services is a simple one, although it could be an unfamiliar environment for pre-SQL Server 2017 (only) administrators; which was the edition that allowed SQL Server to run on Linux.
General information regarding restarting the SQL Server services can be found on this Microsoft Docs page.
systemctl list-unit-files | grep enabled
If your service is not on the above list, it won’t start on the next reboot. View the full by entering the ‘systemctl’ command on it’s own, and enable/disable by replacing ‘start/restart’ with ‘enable/disable’ – more info in systemctl link above.
sudo systemctl status mssql-server
Green-text will show you the service is currently active.
Stop/Start services if you need it down for a while or just run a restart.
Start / Stop:
sudo systemctl stop mssql-server sudo systemctl start mssqsl-server
sudo systemctl restart mssqsl-server
Always a status check at the end to verify (get used to writing it).