I am using OMV 4.1.13-1 on a Odroid HC2 with a 2 TB Seagate Barracuda 3GB/s 5900RPM. I am on speaking terms with it using SMB/CIFS.
It works fine as long as I am seeing files on File Explorer and not the dreaded "This Folder is Empty" . When I need to do
a backup I just reboot OMV; I can then see the files and complete the backup.
I guessing the problem comes from the HD possibly going to sleep or some other state change.
If there is anyone else "out there" that is using OMV 4 on an HC2 with no problems. Can you tell me what HD you are using?