I am a bit stuck here. I have an old 1.x installation which I created from the installation iso and as far as I remember, it detected the storage RAID device and "somehow" integrated it into OMV for usage as a device for the different services.
Now I do a test installation on top of debian 8 and no devices are created. adding a disk doesn't help, I somehow miss the part, where a device is added to the system for usage for instance as an NFS share, s. att.