New server. Installing Windows 2012 R2, but when trying to partition drive it says 'Windows can't create partition....'

hi guys,

So i've been going back and forth with this. I have a server with around 7 x 1TB disks. I want the maximum disk storage possible.

Anyway, so I went and created an array with all of the disks. This created around 5.5TB's of space. Cool. Then when I go to install Windows 2012 onto this disk, it does it. However, it only then shows 2TB's of space leaving 3TB's unallocated and not showing up on the Windows disks. So, I followed instructions as the maximum size for MBR disk is 2TB's and tried this method:


LIST DISK and identify your disk number (from 0 to n disks)

SELECT DISK <n> where <n> is the disk number

CLEAN ALL (Will Take Some Time)


FORMAT FS=NTFS (Will Take Some Time)





If i follow these instructions, I get a disk entirely converted into GPT and then am unable to install Windows onto it.

So now, the only thing that comes to mind is to create my logical drive again as one array. Then using DISKPART, partition this disk and allocate a size for the MBR and another for the GPT so that when installing Windows, I can actually select the allocated MBR disk and install it onto there?

Question is, how do you do that with diskpart? Any ideas?

Thanks peeps for helping
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andreasSystem AdminCommented:
Your machine is booting via a BIOS or VIA legacy mode. This way it will use MBR which only supports 2 TB as a maximum disk size.

You have 2 choices.

Boot you machine in UEFI Mode if possible,

Or devide your RAID into 2 logical disks, one smaller lets say 250GB for the server OS to boot
and the rest. The 2nd disk can then be GPT partitioned from the running server OS. And boot can be from locical disk 1 via MBR mode.

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YashyAuthor Commented:
Hey Andreas,

I'm doing this now. I have to. However, because the disks are 1TB each, I am creating one logical drive with 2 disks raid 1. Then the rest I am setting to Raid 6. I will then set the server OS size to 200GB during the install. I would have liked to have done something like Raid 6 too on there, but I can't as I don't have enough disks and they're too large and I'll be back to where I was. Hopefully it will go smoothly this time:)

Thanks again
David Johnson, CD, MVPOwnerCommented:
you need to boot using an EFI boot to install to a gpt partition.
you need to boot using a MBR boot to install to a MBR partition
you can't mix and match it is one or the other.

If one selects the boot options to boot from DVD in the bios and you try and install you will get the MBR boot by default.  Some bios's allow you to hit a key i.e. F8 on boot to select the boot disk and you if you want to install to a partition >2TB have to chose the UEFI boot that you will see on the DVD Drive.

If you don't have these options available on boot then you have to create a custom dvd that doesn't have the MBR boot.
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noxchoGlobal Support CoordinatorCommented:
I would suggest you getting a 180GB SSD disk or even two for OS, and using the 1TB drives for data only.
You can combine the SSD disks into a software RAID1 via Windows Disk Management.
This way you get best speed and room. And no problems in storage configuration.
I will have to disagree to previous comments about mix and match MBR with GPT as it is possible.

If the machine has the capacity for EFI it will handle both formats, you just have to define the "Initialization mode" for each drive.  Non-EFI BIOS will only Boot from MBR hard drives but EFI BIOS can boot from either.

My recommended solution to your case will be:

Install one or more disk(s) using a RAID of your choice for your OS in MBR (any 500GB will do).
Install your data drives in a different RAID of your choice.

Once you have finished the OS installation, open disk manager select the drive you want to "Initialize" (Second RAID-Virtual Disk) and select "GPT (GUID Partition Table)" then you can create the desired partition(s) on the drive for your data.
YashyAuthor Commented:
Guys, thanks for your help. All of your guidance in its own way paved the way for me to go forward. Hope that makes sense. Excuse the abandonment of the question.
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