First of all, big thanks to everyone as I've always found a solution for my problems on the forum.
Exept for this one...
I've just received my rock pi quad sata hat so happy I could try out a RAID 5 configuration. I had trouble seeing all my 4 drives (4 HDD 2.5" 1To each) but with the help of the forum I finally succeeded.
Now here is my problem : when I try to create a RAID device, none of the hard drive appears on the devices panel. I can see them when I click on disks, and they even appear in the SMART panel. The only difference I see in the SMART panel is the status of 2 of the hard drive is grey instead of green and temperature is N/A. This is weird to me as all the drives are the same size and brand.
I'm not sure what information would be useful but I'm eager to give you some output.
Hope we'll find a way around this.