To create your new instance, you first need to create a directory named like your instance, inside the WIKILOCATION. Then you need to copy the data and underlay directories from your SHARE directory into your instance directory. Finally, you need to copy the wikiconfig.py file from the config directory into the instance directory.
Linux folks need to just type these commands:
> cd $WIKILOCATION > mkdir $INSTANCE # make a directory for this instance > cp -R $SHARE/data $INSTANCE # copy template data directory > cp -R $SHARE/underlay $INSTANCE # copy underlay data directory > cp $SHARE/config/wikiconfig.py $INSTANCE # copy wiki configuration sample file
Note that you just need to keep one underlay directory on your system if you are running multiple wikis (e.g. in a farm.)