Ignoring arguments related to loopback devices ?

Hi All!

I recently reinstalled Zenoss core completely from bottom up (new server; clean os install etc.)
Followed the latest Intallguide (r5.1.2_d1051.16.126)

At page 15, section 4d ; i found some difficulties understanding what exactly is needed.
Page 15 section 4d says: 'Add SERVICED_DM_THINPOOLDEV immediately after SERVICED_FS_TYPE.'

So i interpreted this as followed in my /etc/default/serviced file at line 80:
# Set the driver type on the master for the distributed file system (rsync/btrfs/devicemapper)
SERVICED_FS_TYPE=devicemapper
SERVICED_DM_THINPOOLDEV=/dev/mapper/serviced-serviced--pool

After completing other needed stuff after page 15; i started the serviced:
systemctl start serviced

Instantly i did:
journalctl -flu serviced -o cat

I then noticed the following warning:

Started Zenoss ServiceD.
W0526 18:22:05.445738 31045 storageoptions.go:88] Ignoring arguments related to loopback devices in [dm.thinpooldev=/dev/mapper/serviced-serviced--pool dm.basesize=100G] because a devicemapper thin pool is configured.

I think this not something that is normal :)

What have i done wrong and what must i do to correct this

Thank you in advance for your reply's!

Regards,
David