Hello,

I have already tried on Fedora forum. Mayby here I will find the answer .

I have created new array in that way:
mdadm --create --verbose /dev/md0 --level=mirror --raid-devices=2
/dev/sdb1 missing

Now, I would like to add second partition to this array, but every time I do it via this command:

mdadm --add /dev/md0 /dev/sdc1

I receive: "faulty spare" when I check array's condition via mdadm --detail
/dev/md0 .

These partitions are exactly the same. I have even tried with other HDD but the same model with, again, the same partitions configuration. Again, added partition becomes "faulty spare".

When I create array using these two partitons instead of adding one of them later, everything goes fine.

What is going on? Could you help me?