if (!empty($sorted_target_drives)) {
                $log = $log_prefix . "Drives with available space: ";
                foreach ($sorted_target_drives as $sp_drive => $space) {
                    /** @noinspection PhpUndefinedVariableInspection */
                    $log .= "$sp_drive (" . bytes_to_human($space*1024, FALSE) . " " . ($algo == 'most_available_space' ? 'avail' : 'used') . ") - ";