I would like to change the partition of my HD, an exception is thrown when I try to change or delete the whole disk volume. See the image of my HDD below:
Can anyone help me, please?
Just as Fabby said, you have to stop the array before making any changes. I did not have that in mind, thank you Fabby.
Here is the solution step by step:
# mdadm -S /dev/md0
# mdadm /dev/md0 -r /dev/sda
# dd if=/dev/zero of=/dev/sda bs=1M count=1024
# rm /etc/mdadm/mdadm.conf