Makes sense, and may be the way I go. I have played around with perlbrew before, and it has confused me. I guess I need to better understand perlbrew and how to switch between the systems's perl, and perlbrew, and how to control what perl automated scripts (e.g. via cron) will use. I would also like to understand if the issues I am seeing with cpan are related to version 5.16.3, versus perl 5.10 which I am more experienced with. Additionally, I am specifically needing perl-rrdtool and have not found it for RHEL7, so I may end up installing RHEL6 which comes with perl 5.10 AFAIK.