@JorgeB UD is using the following command to find which UD disks are in a pool, It also tells me which one is the primary member.
/sbin/btrfs fi show mountpoint
Based on what I see in this post, it is causing these btrfs warnings? I guess I'm very confused. Btrfs pools have the same UUID, so what's this all about?
Is there another way to determine the btrfs devices in a pool?