Unable to start SQL Server on Ubuntu 16.04
SQL Server did not start because the OS did not have 3250MB of memory. Was tracked by below command

journalctl -u mssql-server.service -b



Nov 30 00:43:21 OraServer sqlservr[4075]: 
 sqlservr: This program requires a machine with at least 3250 megabytes of memory.


Memory was added and SQL Server was started:

systemctl status mssql-server