I have been working on a solutions that is based on the find *.pm and yum whatprovides, but it needs a lot of parsing of the yum output in order to create a list of rpms and repositories that need to be installed on the new RH machines. Thanks for the tip with the Extutils:Installed. Unfortunatelly, listing the installed modules using instmodsh only shows a tiny fraction of all the installed modules, probably because they are installed outside the default directories.