As an exercise and in order to quickly load my Rockstor box, I have been using Samba and even direct mount of usb NTFS drives (after adding KDE desktop to facilitate plug and play drives).
Then I cam across the great mystery of docker and persisyent storage. UID. In the case of OwnCloud its 33 and somehow samba seem to upload as that too (this might have been a freak as I was overwriting and this probably not changing the uid). In the end the network methods were so slow I just used the drive and copied the files into the OwnCloud Location. To do this I had to change the directory/file owner to my logged in user first. I have now changed back to 33 and all is well.
In my rummage through the filesystem I found that /root is the same as /mnt2/root/root and can create a circular reference when doing a $find / -name blah . I’m guessing this is a Btrfs layout but cant find an explanation. Maybe include that in the docs?