Hi Kevin,
I already rebuilded the lucene indexes but there are still files (573 files, about 100MB size) into the alf_data directory that I am sure aren't into the virtual file system.
Looking into the alfresco database instance I found a table, AVM_NODES.
AVM_NODES seems contain all the references to the alf_data files. The field CONTENT_URL explicitly point the files into the alf_data directory.
So now I'm written a simple standalone jpa application that recursively check which files are inside AVM_NODES and which not.
This application I think could be considered the first step of a virtual file system "scandisk". In the following days I'll write the results of my application.
In the meanwhile, please could you help me to find some documentation about the structure of alfresco database?
Bye,
Vincenzo