magnolia.resources.dir is a property defining the directory from which resources are loaded in a Magnolia instance. This directory is used for file-based resources such as light modules and for overriding classpath resources. The property is configured in
WEB-INF/config/default/magnolia.properties and has the default value
$magnolia.home/modules. To see the current value of the property, go to the Config Info tab in the About Magnolia app.
You can use symbolic links (a.k.a symlinks or soft links) in the resources directory to include light modules located elsewhere on your system.