Hi,
We configured MS 4.1 with an external resource as following:

    /subsystem=modeshape/repository=sample/source=ext01:add(classname="org.modeshape.connector.filesystem.FileSystemConnector",properties=[{"directoryPath"=>"/somwhere"}], readonly="false",projections=["default:/ext => /"], cacheTtlSeconds="5")  

We create large number of nodes in the created external resource. Total size of all nodes are approximately 900 GB.

Although we cannot add any binary storage configuration to store binaries to the repository, in the Wildfly, it create /standalone/data/modeshape/sample/binaries folder and it stores "some files/nodes" under this path. The size of all content under this path is 770 GB. It stores 900 GB files on external file system resource, but totally it stores 1.6 GB files (under external path, and also server directory/internal).