GPT and Type 8e (LVM) Partitions go toghether ??

[Axel Werner]

Hi anybody,

im pretty much lost. i recently installed ubuntu on a new FSC server 
using a hardware raid. the result is a 4TB logical drive (HW Raid, no 
lvm yet).
So while installing ubuntu i partitioned it using 20GB for RootFS (/) 
and left the remaining untouched yet. After successfull installation i 
wanted to create an additional Partition on the raid-drive of Type 8e 
(lvm) so other partitioning apps can recognize there is something on and 
is "in use". But here comes the problem..

For some reason i dont realy know, and without asking me the ubuntu 
installer put a GPT Partition-Table on the giant Drive. I found out 
while i tried to create that Type 8e (lvm) partition with FDISK. Since 
Fdisk warned me, and told me i should use parted i now read lots of docs 
and manuals about it. but im still lost and even more confused.

I was not able to find out HOW TO MAKE an additional Type 8e Partition 
with parted. in fact, all the parted manuals i found do not talk about 
"partition types" anymore, but talking of "filesystems" . well..i 
learned once that partitions and filesystems does not depend on 
eachother. since a partition is an entry in the partition-table and a 
filesystem is a special structure used to organize files within a 
specific "space" within partitions or even simple "files". now there 
should not be partition-types anymore ?!?! WTF???

Could someone pls explain me or point to some better docs explaining me 
that ?? im so f... lost.

HOW TO MAKE USE OF MY REMAINING FREE SPACE ON MY RAID DRIVE showing 
simple partitioning tools "hey this space is in use by LVM" ???

thanks for any help!
regards
Axel