Conversion of Images, through ImageMagic, in DFS cluster environment fails.

Steps to reproduce

Upload a tiff image, to an xml block field, under a DFS cluster environment.
. No image is showed upon "Upload file" button clicked
. eZDFSFileHandlerMySQLBackend::_fetch: error is logged stating File 'var/ezflow_site/storage/images-versioned/... could not be found