Hi, no they are not needed, the system utilities are not stored on the drives on this model. So when you create your RAID 5 in the controller there should not be any partitions and you can use GUID.
I am new to Dell HW and was wondering if the Dell Utility Partition is required? I ask because the XS 6.2 admin guide states that if the Dell Utility partition exists then the disk will be formated using DOS formating instead of GUID. The CO. wants to only but 6x 600gb disks and format it with RAID5 and partition it. Not my recommendation.  Thanks
Xenserver 6.2 install on R720