How to access more than 2 TB of disk space?
Harm Millaard Feb 25, 2010 10:28 AMIn the past I have posted on Adobe Forums: Storage rules for an editing rig. Some... and on Adobe Forums: To RAID or not to RAID, that is the... .
With disk sizes increasing all the time and 3 TB models announced, people are often confronted with the limitations of Windows, especially when using Raids. I have had to help people in setting up their raid configuration, and while it is not difficult, if requires some knowledge on how to set it up. I thought this might be of interest to help you install large raids on your own system and correct the limitations of Windows.
The problem.
You have a number of large disks, say 1, 1.5 or 2 TB disks and you want to raid them and then discover that Windows does not allow volumes larger than 2 TB. You can't really access the unallocated space in a standard way. That is a shame, because in your case (example), with 4 x 2 TB disks, you had hoped to access 8 TB but can only access 2 TB and having 6 TB of unallocated space is a serious waste. This can easily be corrected.
Some Background.
An array is a number of physical hard drives, that are seen as one disk by Windows. This will show you how to convert a MBR (Master Boot Record) array/disk to a GPT (GUID - Globally Unique Identifer) array/disk in Windows Disk Manager. By default Windows uses MBR disks or arrays.
While all Windows can boot from a MBR disk or array, you can only boot from a GPT disk if you have an operating system (see below) that supports GPT and your motherboard has a EFI BIOS and is enabled.
You can still have a separate GPT disk as a data disk if your operating system (see below) supports reading a GPT disk, even if your system disk that Windows is installed on is still a MBR disk.
Note.
Differences Between MBR and GPT Disks:
* MBR disks are supported (readable) by all Windows operating systems.
o GPT disks are only supported (readable) by Windows server 2003 SP1 +, XP 64-bit, Vista, Windows 7, Windows Server 2008.
* MBR disks use the standard BIOS partition table.
o GPT disks use extensible firmware interface (EFI).
* MBR disks supports up to 2TB per single partition.
o GPT disks supports up to 256TB per single partition in Windows.
* MBR disks supports up to 3 Primary partitions and 1 Extended partition with up to 128 logical volumes in the extended partition.
o GPT disks supports up to 128 Primary partitions.
* Removable disks are MBR disks by default.
o Removable disks cannot be converted into a GPT disk.
Warning.
* You must be an administrator to do this in Windows.
* Before you convert a disk, close any programs that are running on or from that disk.
* Before you convert a disk, be sure to backup anything that you do not want to lose on that disk. Converting the disk requires that all partitions and volumes are deleted on the disk first.
How to correct this limitation.
1. Right click on My Computer.
2. Select Manage.
3. Select Disk Management.
4. Select the disk you want to modify, right click on it and select Delete Volume until the whole disk is unallocated.
5. Right click on this disk that you want to convert and select Convert to GPT disk.
6. When finished, you can confirm that the disk is a GPT disk if you right click on the disk and it has Convert to MBR disk instead now.
7. Now you can format the GPT disk and have all the space available for use.
8. Close Disk Management.
This is the easiest way to allow for single volumes of 256 TB or less. I hope this was helpful if you have been struggling with this problem.






