Assembly is done using the provided Assembler:

@Override
public void assemble( ModuleAssembly module )
    throws AssemblyException
{
    JdbmEntityStoreAssembler assembler = new JdbmEntityStoreAssembler( Visibility.application );
    assembler.assemble( module );
}

Here are the configuration properties for the JDBM EntityStore:

public interface JdbmConfiguration
        extends ConfigurationComposite
{
  [...snip...]

   @Optional
   Property<String> file();

   // JDBM RecordManager options

   @UseDefaults
   Property<Boolean> autoCommit();

   @UseDefaults
   Property<Boolean> disableTransactions();
}

file is optional and represent the file where the JDBM EntityStore will keep its persisted state.

It defaults to System.getProperty( "user.dir" ) + "/qi4j/jdbmstore.data" If the given path is not absolute, then it’s relative to the current working directory. If you use the FileConfig Library then this property value is ignored and FileConfig is prefered.