We have got kind of same issue recently installed new Dell R630 with (Perc H700 controller) with ESXi 5.5 Free with 6x600 GB new hard drives and reconfigured RAID5 with 2.76 TB of usable space. However, I cannot increase the datastore to above 2.0TB. I can see total capicity 2.76TB .I can't even add new data store as I can't see available disk space.
Thanks
Deepak