Steps to reproduce:

1. create item vfs.fs.free or used or pfree for /
2. check data in latest data
3. data differs from local values on  node

Client reports locally:

 $ /usr/local/sbin/zabbix_agentd -t vfs.fs.size[/,free]
vfs.fs.size[/,free]                           [u|2934607872]
$ /usr/local/sbin/zabbix_agentd -t vfs.fs.size[/,pfree]
vfs.fs.size[/,pfree]                          [d|64.646081]
$ /usr/local/sbin/zabbix_agentd -t vfs.fs.size[/,used]
vfs.fs.size[/,used]                           [u|1604882432]

latest data however shows different values:

We see this on all of our PFsense-boxes (FreeBSD 11.3-STABLE).

All systems - even though they have different disk size - report the same values, which is wrong: