librenms-librenms/includes/polling/mempools/netspire.inc.php

<?php

$usage = str_replace('"', '', snmp_get($device, 'netSpireDeviceStorageUsed.0', '-OQv', 'OACOMMON-MIB'));

if (is_numeric($usage)) {
    $mempool['total'] = 100;
    $mempool['used'] = $usage;
    $mempool['free'] = 100 - $usage;
}