I had a drive 2 failure that WD determined was covered under warranty. Instead of sending me a new drive, there was some minor concern that the problem might have been the drive interface, so they sent me a whole new unit. That’s fine, except now I have an unexpected problem. I first started up the new unit and got the firmware up to date and made sure everything worked normally. I then took the good drive out of the original unit and placed into the new unit in order to rebuild the RAID on the new new unit. When I started it up, the new unit gave a message like this: “New drive detected in slot 1. RAID will be rebuilt from Drive 2. All data on Drive 1 will be erased.” Well, obviously, that’s not what I wanted. I wanted the exact opposite actually, to rebuild the RAID from Drive 1. Unfortunately, it appears that isn’t an option.
Try to put the good drive on the new enclosure while its off, then you might get an option to do raid roaming, then you will put the new drive there to see if the unit rebuilds correctly. Hope this helps
Here is what I had to do. Since the new unit had no method by which to designate which drive you wanted to rebuild the RAID from, I proceeded to take both of the new hard drives out of the new unit. Then, one at a time, place those drives into the old unit and rebuild the RAID there on each of the new drives. I then placed the 2 built drives back into the new unit and started it up. The new unit then recognized the RAID roaming for both drives and gave me the option to integrate them into the new unit. It appears to have worked, it looks like all my data is still there. Kindda of a pain though.
If the whole point of the RAID (mode 1) is to make it easy to swap out a bad drive when it fails, then you would think the unit that runs the drives would give you the option to build the RAID from whatever drive you wish to select.