Part all the disks.

partedmagics

#!/bin/bash
#this echoes EVERYTHING
set -x verbose
echo "THIS SCRIPT IS DANGEROUS do not be stupid"

apt-get install lvm2 mdadm 

# $disks should be replaced with the last char on each disk you want to apply this to
#disks="a b c d e f"
disks="a b c d e f g h i" #EDIT THIS LINE 
#totalnumberofdisks == total number of disks
numdisks="8" #EDIT THIS LINE 

for i in $disks ; 
  do
  # create the partition table
  parted -s -a optimal /dev/sd$i mklabel gpt ;
  # create the gpt boot volume
  parted -s -a optimal /dev/sd$i mkpart non-fs 0 2;
  # create the boot volume
  parted -s -a optimal  /dev/sd$i mkpart ext3 2 512 ;
  # set the rest of it ready for the storage array
  parted -s -a optimal  /dev/sd$i mkpart ext3 512 100%; 
  # mark the partitions correctly
  parted -s /dev/sd$i set 1 bios_grub on;
  parted -s /dev/sd$i set 2 raid on;
  parted -s /dev/sd$i set 3 raid on;
done
#create your /boot volume 
for i in $disk; do alldisks2="$alldisks2 /dev/sd${i}2"; alldisks3="$alldisks3 /dev/sd${i}3"
mdadm --create /dev/md0 --level=mirror --raid-devices=$numdisks $alldisks2
#create your storage array
mdadm --create /dev/md1 --level=6 --raid-devices=$numdisks $alldisks3
pvcreate /dev/md1
vgcreate storage /dev/md1
#root volume mount it as / format it as whatever (recommned ext4)
lvcreate storage -L 50G -n root
#format the root vol
mkfs.ext4 /dev/storage/root

#Make me a swap volume
lvcreate storage -L 8G -n swap
#make it a swap
mkswap /dev/storage/swap

#creates your home partition this is where verything goes in the install mount it as
#/home format it as whatever (recommned ext4)
lvcreate storage -l 100%FREE -n home
#format the home dir
mkfs.ext4 /dev/storage/home


echo 'wait a while before restarting'

Once you add the disks into this script it will do the following.

create a 2 MB in size volume at the start of the disk for the efi boot stuff

create a 512MB vol that you should use as /boot (this should be a raid 1 of all disks in your array)
create a rest of disk vol for the main storage array this should be turned into lvm once raided
root should be in here somewhere.