Sometimes its a big problem to install OS on hdd’s after hardware raid. Because hdd contains RAID metadata and OS can’t be installed.
To remove RAID metadata, do following:
dd if=/dev/zero of=/dev/sda bs=512 count=20
– removing first 20 sectors of the drive
then check number of sectors via command fdisk -s /dev/sda
dd if=/dev/zero of=/dev/sda seek=(number_of_sectors – 20) bs=1k
– removing last 20 sectors of the drive
or
dd if=/dev/zero of=/dev/sda seek=$(( $(fdisk -s /dev/sda) -20)) bs=1k
Do this on all drives with RAID metadata