Thanks, for the reply
I've shutdown Unraid and unplugged 2 of the onboard Sata connectors, and then plugged in 2 of the sata connectors from the 2nd M.2 Sata 3.0 riser card which are giving udma crc errors.
Restarted Unraid and only 14 of the 18 hard drives appeared in the unassigned disk list - the 2 problematic drives did not appear on the list - going to unassigned plugin did not located them. 4 Drives appeared in the Historical Devices list of the main Unraid Tab - corresponding to the 2 disconnected drives and the 2 newly connected problematic drives. Removed the problematic drives from the Historical Devices list , rebooted and executed the unassigned plugin. The 2 problematic drives do not appear on the unassigned devices.
Do i need to remove all the historical devices in order for the problematic drives to appear on the unassigned devices list?