Had an issue with $key_blocks_used that should read $Key_blocks_used – so, here’s the diff if you don’t feel like downloading the new release, you can just change those two variables on lines 695 and 697 in bin/kontroll-reporter-5.0.x_linux-x86-2.0.1.pl as follows:

695: $key_buffer_fill = ($key_blocks_used / $key_blocks_total);
607: $key_buffer_ratio = (100 * ($key_blocks_used / $key_blocks_total));