Resize RAID partition in Windows Server 2008

Updated on: November 16, 2019

This article introduces how to resize raid partition in Windows Server 2008 r2, resize raid 0/1/5/10 virtual partition without losing data.

Resize raid partition with diskpart or Disk Management

Comparing with physical hard disk, hardware raid arrays provide higher performance, fault-tolerant, larger storage capacity or other benefits, so they are common used for servers. However, while resizing raid partition on Windows 2008 server, there is no difference with resizing physical disk partition. The benefits are realized by raid controller, to Operating System and programs, raid array virtual disk are the same with physical device.

Windows Server 2008 has native diskpart command and Disk Management which is able to extend partition without losing data. However, they can only extend NTFS partition by deleting the right contiguous one. Unallocated space shrunk from a partition cannot be extended to other one.

Extend Volume disabled

As you see in the screenshot, Extend Volume greyed out for both C and E drive after shrinking D, this is because:

The 20GB Unallocated space that shrunk from drive D is non-contiguous to C and is on the left of E, therefore, Extend Volume doesn't work for these two partitions.

You need 3rd-party software to make Unallocated space on the left or move from right to the left.

In most of servers, the right adjacent partition (D: or E:) is used for programs or some Windows services, so you cannot delete it. That means you cannot extend system partition C in Windows Server 2008 with Diskpart command or Disk Management.

How to resize raid drive with NIUBI Partition Editor

Comparing with Windows native tools, NIUBI Partition Editor is much more powerful to resizing disk partition.

While resizing raid partition in Windows Server 2008 (and R2), firstly check if there is free unused space in the same disk. If yes, it is very easy. You just need to shrink a partition to get Unallocated space, and then add to the partition that you want to expand, no matter the raid array is RAID 0, 1, 5, 10, etc or built with any brand of controller/card.

Download NIUBI Partition Editor and you'll see the main window with disk partition structure and other information on the right, available operations to selected disk or partition are listed on the left or by right clicking. In my test server, there is drive C, D, E and System Reserved partition in same Disk 0.

NIUBI Partition Editor

How to resize partition C and D on RAID array for Windows 2008 server:

1: Right click the right contiguous partition D: (in some server, it is E:) and select "Resize/Move Volume", drag left border towards right in the pop-up window. You may also enter an amount in the box behind "Unallocated space before".

Shrink D

Then drive D is shrunk and Unallocated space is made on its left.

Shrink D

2: Right click system C: drive and select "Resize/Move Volume", drag right border towards right in the pop-up window.

Extend C drive

Then Unallocated space is combined into C drive.

Extend os drive

3: Click Apply on top left to execute.

As long as there's free space, you can resize either system partition or data volume easily, follow the steps in the videos to resize raid virtual partition in Windows Server 2008 R2.

How to resize and extend system partition C:

Video guide

How to resize and extend data partition (here is D):

Video guide

Better than other software, NIUBI Partition Editor is much safer and faster because of its unique technologies, no matter you want to resize partition on raid array, physical disk or VMware/Hyper-V virtual disk.

Resize raid partition with larger disks

In some old servers, system disk is not large, there may be only single C drive, or there is not enough free space in all other partitions on the same disk. In that case, check if your controller support RAID expansion. If yes, additional space will be shown as Unallocated on the end of original virtual disk after rebuilding raid array with larger disks. Then follow the steps above to resize partition(s) with the Unallocated space.

If your raid controller has no such ability, the size of raid virtual disk will be the same with before even if you rebuild with larger disks. In that case, you need to copy to other larger physical disk or another raid array.

Besides resizing and copying disk partition, NIUBI Partition Editor helps you merge, convert, defrag, hide, wipe, scan partition, etc.