quoted

....How, I don't know.

Did you check the "fdisk -lu /dev/sda" output?

Yes. 63, so I still went on and repartitioned as described in Trial #[123].

I'm thinking that it could have been something left behind by the Intel Matrix RAID volume management... Maybe Neil Brown could give an explanation to this. I also noticed that if one re-partitions the exact same way, the RAID superblock information becomes available again, that is, partitioning or disassembling a RAID device does not threcken those records off the disks. Therefore, even if one does not create a partitioned md array, it will be, on its own! Actually it makes sense, since partitioning does not involve alteration of records throughout the disks... I just thought it would be interesting to share all this.

In the near future I will describe my story in a single post, maybe it will inspire some developers to address certain points in their documentation work.

Thanks again to All,
Tibor