Okay Harald I found what my problem was caused by and I fixed it. I rebuilt the new RAID box and during the create I specified /dev/md1, which of course didn't work since /dev/md1 does not exist! So I had to do a mknod to create md1 then run the 'mdadm --create...' which then did it's thing. Then I made sure that the mdadm.conf file was using the UUID numbers from the RAID boxes, my mount point existed and so on, then reboted which resulted in the box being mounted properly and udev created the proper /dev/md1 for the box being there. Problem though: How could one have gone into the superblocks and modify the /dev/md0 tag to change it to /dev/md1? I had to blow away the partitions and then do a total rebuild to do it, that is not a good way to manage the RAID boxes efficiently, but for me now both RAID boxes work. Regards Bill