# Assumes top hash key is in the form:
#    hostname:platform:env
# and the second-level hash key is:
#    target
# and since the lowest level of your example is always the
# same structure, we put the values in an array:
#    [0] = total_capacity
#    [1] = current_free_space
while (my ($hostkey,$targets_href) = each %{$stuff}) {
   # *This* report doesn't care about prod/dev or OS, it's
   # just to warn about disk space problems, so only need
   # $host...  Other reports may want other bits
   my ($host,undef) = split /:/,$hostkey;
   print "\n*****\n* $host\n*****\n\n"
   .     "FreeSpc  %Free Target\n"
   .     "-------- ----- -----------------\n";
   while (my ($target,$cap_href) = each %{targets_href}) {
       my $pct_free = $cap_href[1] * 100.0 / $cap_href[0];
       if ($cap_href[1] < $warn_pct * $cap_href[0]) {
          printf "% 8u %5.3f %s\n",
             $cap_href[1], $pct_free, $target;
       }
   }
}