Disk usage wrong size

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1

Server FreeBSD 10.3
I got a storage backup2, df -h show this:

 Filesystem             Size    Used   Avail Capacity  Mounted on
/dev/mirror/backup2    3.5T    3.2T     91G    97%    /mnt/backup2

And librenms shows this(same mount point):

Size          Free                  Used
3.52TB    379.43GB(!!)              89.49%

Why librenms show me wrong numbers? How can I fix it?

2

Output of
./poller.php -h HOSTNAME -m storage -d

4 
root@librenms-s:/opt/librenms# ./poller.php -h 10.15.250.8 -m storage -d
LibreNMS Poller
===================================
Version info:
Commit SHA: e9e30c5e98d28c486b7a81974513b375b42a8d79
Commit Date: 1531164326
DB Schema: 253
PHP: 7.0.30-0ubuntu0.16.04.1
MySQL: 10.0.34-MariaDB-0ubuntu0.16.04.1
RRDTool: 1.5.5
SNMP: NET-SNMP 5.7.3
==================================DEBUG!
Updating os_def.cache... Done
Starting polling run:

SQL[SELECT * FROM `devices` WHERE `disabled` = 0 AND `hostname` = '10.15.250.8' ORDER BY `device_id` ASC]
./poller.php 10.15.250.8 2018-07-10 09:11:56 - 0 devices polled in 0.256 secs
SNMP [0/0.00s]: Get[0/0.00s] Getnext[0/0.00s] Walk[0/0.00s]
MySQL [5/0.00s]: Cell[2/0.00s] Row[0/-0.00s] Rows[3/0.00s] Column[0/0.00s] Update[0/0.00s] Insert[0/0.00s] Delete[0/0.00s]
RRD [0/0.00s]: Update[0/0.00s] Create [0/0.00s] Other[0/0.00s]
5

10.15.250.8 does not seem to be a valid device.