Kemal Cholovich1 Install it first: https://docs.microsoft.com/en-us/sql/linux/quickstart-install-connect-ubuntu?view=sql-server-2017
2 Check:
~$ sudo systemctl status mssql-server
3 Do what you need:
~$ sudo systemctl stop mssql-server
~$ sudo systemctl start mssql-server
~$ sudo systemctl restart mssql-server
