Normally when I have a drive which contains raid metadata e.g. from fakeraid or a hardware raid card I can get rid of it with:
dmraid -r -E /dev/sdX
Or if that doesnt work, doing a simple dd if=/dev/zero of=/dev/sdX normally works
But I have 4 WD RE4 drives here and neither option seems to work. dmraid just gives me a CRC error when it reads the drive. I know the drives are fine and theyve been checked with smart + WD diagnostics anyway
The actual error on dmraid is:
ddf1: physical drives with CRC 5CD0C0DB, expected FFFFFFFF on /dev/sda ERROR: ddf1: Cannot find physical drive description on /dev/sda! ERROR ddf1: setting up RAID device /dev/sad nor aid disks and with names: "/dev/sda"
Gives the same CRC error for all disks so clearly something strange the raid controller did
I've even formatted them with mdadm through rescuemode to see if that would overwrite it but no difference.