Partition Bigger than 2TB

[techie08]

Hi

 

Ive just bought a server with 8 2TB disks in and I wonder how you can create the windows partition on volumes bigger than 2TB?

 

Thanks

[Michael]

Excellent question, but according to this article, by increasing the allocation size to 64KB, you can have single volumes up to 256TB.

[techie08]

I can create the raid drive group which is 3tb (3 x 2tb Raid 5) but when installing 2012, it wont allow me to create a partition bigger than 2tb. Is it the raid stripe size I have to se as 64kb?

[Koldov]

Hi,

 

Do you have the following prerequisites enabled/configured?

 

In order for an operating system to fully support storage devices that have capacities that exceed 2 terabytes (2 TB, or 2 trillion bytes), the device must be initialized by using the GUID partition table (GPT) partitioning scheme. This scheme supports addressing of the full range of storage capacity. If the user intends to start the computer from one of these large disks, the system’s base firmware interface must use the Unified Extensible Firmware Interface (UEFI) and not BIOS.

 

Windows support for hard disks that are larger than 2 TB

 

Is there any reason you want a Windows partition of more than 2TB? Am I right that 3 x 2TB disks in RAID5 is going to give you 4TB of actual capacity?

 

Also is 3 x 2TB disks in RAID5 the best choice for the operating system? Are the other 5 x 2TB disks for data etc.?

 

I only ask because I am looking to purchase a new server and I'm very interested in how to set up all the disks... I have been advised that the OS is a 2 disk RAID1 setup and 4 disk minimum RAID10 for the data etc. Also that my Server OS partition would be OK around the 120GB range.

 

Kol.

Edited March 28, 2014 by Koldov

[Michael]

The way I understand it is your system BIOS needs to be using UEFI rather than MBR, which has a 2.2TB limit, you need an OS which supports UEFI (and of course Server 2012 does), plus you'll need the latest RAID drivers.

 

When you initialise the hard disk or RAID array, you'll given the choice between MBR or GPT. Selecting GPT will allow you to have a 2TB+ single volume. The cluster size (which I wrote above) also plays a part, just set the allocation size accordingly to your needs. 4KB allows volumes up to 16TB in size.

[Michael]

Hi,

 

Do you have the following prerequisites enabled/configured?

 

In order for an operating system to fully support storage devices that have capacities that exceed 2 terabytes (2 TB, or 2 trillion bytes), the device must be initialized by using the GUID partition table (GPT) partitioning scheme. This scheme supports addressing of the full range of storage capacity. If the user intends to start the computer from one of these large disks, the system’s base firmware interface must use the Unified Extensible Firmware Interface (UEFI) and not BIOS.

 

Windows support for hard disks that are larger than 2 TB

 

Is there any reason you want a Windows partition of more than 2TB? Am I right that 3 x 2TB disks in RAID5 is going to give you 4TB of actual capacity?

 

Also is 3 x 2TB disks in RAID5 the best choice for the operating system? Are the other 5 x 2TB disks for data etc.?

 

I only ask because I am looking to purchase a new server and I'm very interested in how to set up all the disks... I have been advised that the OS is a 2 disk RAID1 setup and 4 disk minimum RAID10 for the data etc. Also that my Server OS partition would be OK around the 120GB range.

 

Kol.

 

I agree that a RAID1 for the OS, but then you could argue if you have multiple DCs, creating a RAID5 array then partitioning as required for the OS and data also works well.

 

You can use RAID10 for data, but it can be quite expensive. RAID6 is generally becoming more popular as you can lose a maximum of two drives before the whole array is lost. RAID10 can only lose one drive/span, as is the case with RAID5.

[Koldov]

Sorry to hijack the thread a little...

 

I agree that a RAID1 for the OS, but then you could argue if you have multiple DCs, creating a RAID5 array then partitioning as required for the OS and data also works well.

 

You can use RAID10 for data, but it can be quite expensive. RAID6 is generally becoming more popular as you can lose a maximum of two drives before the whole array is lost. RAID10 can only lose one drive/span, as is the case with RAID5.

 

So you would say RAID1 is generally used when only 1 DC is in operation i.e. when it is required for high availability of 1 individual server?

 

Is RAID10 more expensive than RAID6, I thought they both used a 4 drive minimum? Not sure of the calculations if drives are increased though.

 

Kol.

[Michael]

This is just my professional opinion and others may agree/disagree -

 

If you have a domain with a single DC, then I'd typically recommend RAID1 for the OS and RAID5 or RAID6 for data.

 

If you have multiple DCs in a domain, then I'd recommend either a RAID5 or RAID6 array (per server), which is then split into two volumes - for the OS and for data.

 

Even in a worse case scenario, you can seize roles from one DC to another (if it failed), but you could argue that having multiple DCs your data is also going to be split also adding more redundancy.

 

You could of course introduce Hyper-V for non critical purposes (again across RAID5 or RAID6), but I wouldn't recommend this all on one physical server or DC.

 

RAID5 needs 3 physical drives and RAID6 needs 4 physical drives minimum.