SECTION IV: INSTALLING WINDOWS SERVER 2012
It’s finally time to install Windows Server 2012!
Actually, no it’s not. Do you remember that part about UEFI when we listed what items to get? Well, that matters now (to a certain degree). If you don’t have a UEFI BIOS motherboard, no need to be worried. The install process will be a tad different. For UEFI users, you can install Windows Server 2012 as you normally would.
UEFI VS. NON-UEFI
Before we begin install, let us first go through what exactly UEFI/EFI is. BIOS’ traditionally only allowed booting in MBR (Master Boot Record) drives. The usual person, even today, doesn’t install an operating system on a large 3TB+ drive; for those that do however, there is UEFI. What UEFI does is allow us to boot into GPT (GUID Partition Tables), and requires a 64-bit operating system (which WS 2012 exclusively is). The Micrsoft GPT FAQ is a brilliant resource if you want to read more; the maximum NTFS GPT volume sizes come from it:
So what does it matter? Well, MBR doesn’t allow booting into volumes greater than 2.2TB in size. In fact, Windows will list the maximum capacity of the drive at 1.91TB for a 4k cluster size (default). This is a problem for us, because our primary boot drive is a 19TB RAID 5 volume. GPT on the other hand can support booting into the array no problem (8k default cluster size).
Where the problem comes into play is the installation media and BIOS interacting. If you have UEFI BIOS, the boot device manager will give you the option of loading normal BIOS or UEFI BIOS (will mention which one is which). This will tell the Windows installer that there is a >2TB drive present in the system and that it can be converted into GPT, and used as a single primary OS volume as we intended all along.
Fact is, it may not work. UEFI has been integrated into motherboards, and while not being brand-spanking new, it’s not very reliable either. Take our motherboard for example. It has EFI support for CD/DVD media, BUT NOT USB. This forces us to install a DVD drive, burn the OS onto a DVD, and cross our fingers in the hopes that everything proceeds correctly. It’s just way too much hassle and not enough trust for this to be viable. If your motherboard natively supports UEFI though, you have nothing to lose. The problems with Gigabyte’s Hybrid EFI are also documented in this blog post in case you want to read more.
Now, what if you don’t have UEFI? We can tell you right off that using the entire RAID array as your primary OS boot drive is out of the question. Your best bet is to either install the operating system on a lone drive separate from the array, or to break the array down to 17TB and and use the rest of the 3TB space as your OS partition. If you don’t do this, you end up with 17 terabytes of unusable space. The Windows installer will read the entire 19TB volume, but without UEFI BIOS, will designate it as MBR instead of GPT. So you boot into Windows Server 2012, only to find 1.91TB of usable space, and the rest unusable:
Because the installer made a partition based on MBR, and because our entire array is now MBR, the unusable space cannot be touched and will remain as “unallocated space” under the Windows Storage Manager. Remember, the array shows up as one drive, not the eight drives separate. Therefore, we can’t do anything to the unallocated space because the entire drive is MBR – no conversion into GPT either because we’re booted into Windows. Hooray! 17TB of useless space.
Why can’t we convert to GPT before installing Windows? You can try, but trust us when we say, these WILL NOT work if you do not have UEFI/EFI. The first is converting the RAID array into GPT and then assigning the array a 512k strip size and an 8k cluster size so it reads the drive properly (check the Windows cluster tables above to see which size you need to set for maximum capacity to be utilized). Here are the scripts you need to run:
To get into the Command Prompt (CMD) press SHIFT + F10. If you want to try out a few extra commands, they are as follows. Read the Microsoft Diskpart.efi GUID article for extra tips and steps:
select disk 0
create partition primary align=512
format fs=ntfs unit=8K quick
Didn’t work? We told you so. The conversion into GPT can only be done in the operating system, and not on the main OS drive while Windows is running. If you try and convert your OS boot drive into GPT via the method we listed above, the Windows installer will see right through it, yielding the message that Windows cannot be installed on GPT without a certain BIOS (UEFI):
Comparing this to GPT, we can see how it splits the volumes nicely and still allows us to use our entire array:
Again, your best bet is what we said before if you don’t have UEFI/EFI: grab an SSD, make it your primary OS boot drive, install Windows Server 2012 on it which without UEFI will classify it as MBR (we don’t care, it’ll be less than 2.2TB anyway).