raid array with 3T disks and GPT partition

Hi,

I'm trying to create a raid6 array from 10x3T disks. Since disks > 2T
must use the GPT partion table I used parted to created a single
partition on each drive with the correct GPT partion type.

Now how do I make sure that these partitions have the correct "raid
autodetect" (fd) id? Is it even still needed? I didn't find any way to
set that flag in (g)parted.

Thanks,