From the ArcSDE Administration Command Reference:
Beginning with ArcGIS 10.1, you must use a geoprocessing tool or
Python script to create a geodatabase. For geodatabases in Oracle, SQL
Server, and PostgreSQL, if you can use the default settings, use
the Create Enterprise Geodatabase tool or a Python script that calls
this tool. If you want to configure your database before creating a
geodatabase, use the Enable Enterprise Geodatabase tool or a Python
script that calls this tool.
Which means you cannot create a geodatabase with ArcSDE command line tools, you have to use ArcGIS Desktop or Engine Developer Kit with Python installed (which will give you access to the arcpy). You can still use the ArcSDE cmd to create an ArcSDE Windows service.