Restart MSSQL Server on Linux (Ubuntu).
Microsoft is recommend do that like this:
-- Get service state
sudo systemctl status mssql-server
-- Stop service
sudo systemctl stop mssql-server
-- Start service
sudo systemctl start mssql-server
-- Restart service
sudo systemctl restart mssql-server
For Ubuntu I am prefer restart service by this method:
service mssql-server status
service mssql-server stop
service mssql-server start
service mssql-server restart