When I installed OMV on the SATA HAT with 4 drives, the drives are recognized fine but the webUI does not allow to create a RAID on them. When I created the RAID manually by command mdadm, it was created fine and also shows up in the OMV webUI.
In the OMV forum they do not recommend RAID on the SATA HAT because it is viewed as an USB device. They also say it is not recommended due to stability issues and a RAID would not bring extra security.
The same seems to apply to LVM, OMV did not allow me to create a LVM. Once I created it manually, it works fine.
Ok, after a few days I made my own experience. All of a sudden, the RAID 5 failed and cannot be restored. This is really frustrating, after I had put a lot of work and money into setting up the box.
Being thankful again to have a working backup. This contains all my music, including a lot of payed downloads.
Now I need to think about another concept, maybe different hardware.
Ok Iām fed up with this hardware. Another approach with a minimal raspbian system without OMV installed had the same result. After some ours of operation the RAID just breaks down. This is not a reliable system.