I still have troubles here. I found out something interesting: I used zero-superblock with --force on the disk and the partition, and i used dd to zero over the end of the partition and disks.
It works now, but when i add the spare-drive to the RAID i get the "error: found two disks with the index 4 for RAID md0." again.
When i remove the spare and zero the superblock, it works again.
I still have troubles here. I found out something interesting: I used zero-superblock with --force on the disk and the partition, and i used dd to zero over the end of the partition and disks.
It works now, but when i add the spare-drive to the RAID i get the "error: found two disks with the index 4 for RAID md0." again.
When i remove the spare and zero the superblock, it works again.