Prior to your upgrade, you might want to get, and install HTML::Perlinfo. Then create the following, and open it in your web browser (other possibilities exist for the CLI)

#!/usr/bin/perl -T

use HTML::Perlinfo;
use strict;

print "Content-type: text/html\n\n";

perlinfo();
[download]

This will give you a wealth of information, regarding your current Perl installation. Not the least of which, are all the Modules you currently have installed. Think of it, as Taking Inventory. :)

BEWARE do delete the script I provided above, after you've used it. Because you DO NOT want others to have access to this information. :)

Best wishes.

--Chris