Create initial Informix dbspace on a new server from script

I'm able to create a new dbspace using the semi-gui tool onmonitor (running a headless Linux server) But how can I do this from cmd-line / script? It seems you can use onspaces like

onspaces -c -d $DBSname -p $DBSfile -o 0 -s 153600

But AFAIK it require the IDS server is running in one of these modes online, quiescent or administration and this seems only possible to start the server if there already exist a dbspace. Or am I missing something? Can you really only setup a new server using the init menu in onmonitor?