librenms-librenms/includes/discovery/storage.inc.php

<?php

$valid_storage = [];

// Include all discovery modules
$include_dir = 'includes/discovery/storage';
require 'includes/include-dir.inc.php';

// Remove storage which weren't redetected here
$sql = "SELECT * FROM `storage` WHERE `device_id`  = '" . $device['device_id'] . "'";

d_echo($valid_storage);

foreach (dbFetchRows($sql) as $test_storage) {
    $storage_index = $test_storage['storage_index'];
    $storage_mib = $test_storage['storage_mib'];
    d_echo($storage_index . ' -> ' . $storage_mib . "\n");

    if (! $valid_storage[$storage_mib][$storage_index]) {
        echo '-';
        dbDelete('storage', '`storage_id` = ?', [$test_storage['storage_id']]);
    }

    unset($storage_index);
    unset($storage_mib);
}

unset($valid_storage);
echo "\n";