Using DISKPART - Missing HD Space?

Hello. I've setup a new Hyper-V 2012 R2 server on a new HP RAID-6 box with a single 4TB logical disk (to keep it simple). However, I'm unable to realize all 4TB as shown by DISKPART (as I'm in the thin "shell" layer, so the VMs and such should be a moot point in all this). Output as follows:

DISKPART> select disk 0

Disk 0 is now the selected disk.

DISKPART> list disk

Disk ### Status Size Free Dyn Gpt
-------- ------------- ------- ------- --- ---
* Disk 0 Online 4471 GB 0 B

DISKPART> list partition

Partition ### Type Size Offset
------------- ---------------- ------- -------
Partition 1 Primary 350 MB 1024 KB
Partition 2 Primary 287 GB 351 MB
Partition 3 Primary 1760 GB 288 GB

DISKPART> create partition primary

Virtual Disk Service error:
There is not enough usable space for this operation.

Any idea why I can't the setup the rest of the 2.xTB of space from the original 4TB for my purposes? As it stands, I have unallocated space which I dearly need.

Thanks all.

NightHawk10Asked: 2014-12-09

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LVL 88

rindiCommented: 2014-12-09

If your Server has an UEFI BIOS, then it should work, provided you have UEFI turned on. You will then need to make the disk a GPT disk so more than 2 TB are available. If it doesn't have an UEFI BIO, you will have to use an MBR disk, and MBR disks only support a maximum of 2 TB.

Windows, can only boot from GPT disks if you have an UEFI BIOS. Otherwise you will have to create 2 RAID volumes, one small for the MBR disk you want to install the OS to and boot from, and the other disk can be GPT.

LVL 98

Lee W, MVPTechnology and Business Process AdvisorCommented: 2014-12-09

Additionally, MBR disks can only have 4 partitions. If you have more than 3 primary, you want to create 3 primary and one extended, placing logical drives in the extended partition.

NightHawk10Author Commented: 2014-12-09

Thanks rindi, you are right, my Proliant DL380 gen 8 does NOT support UEFI so my 4.TB logical volume is all for naught! Back to the teardown/rebuild process. Will remember the window boot 2TB limitation from now on.