Q: What should I take into consideration before adding / changing / upgrading controllers and / or Mother Boards, or BIOS settings that affect hard drives?
Q: Why are some of my disks / RAID missing or not displayed properly in WebGUI after adding a new controller to the server, changing BIOS settings or changing to a new Mother Board?
A: Device numbers reported by the BIOS and assigned by the OS will almost certainly change as a result of the new / additional hardware. This will confuse you and the XigmaNAS WebGUI. The WebGUI may show disks as missing but your RAID array or ZFS will still work, this is because they rely on Metadata written on the drives themselves thus they can continue to function, but you will not be able to adequately manage them. Plan ahead before you upgrade especially if you are using ZFS or iSCSI, it will be easier.
If you failed to plan ahead, Don't Panic! This situation can be fixed: