Cannot Extend Volume in Windows Server 2008 R2 - How to Fix

by James, Updated on: October 16, 2022

Better than previous Windows Server 2003, Server 2008 native Disk Management has new Shrink Volume and Extend Volume functions to help change partition size without losing data. When a server runs out of space, it can't be better if you can extend disk partition without wasting a long time to recreate partitions and restore everything from backup. However, many people feedback that they cannot extend volume in Server 2008 Disk Management, because Extend Volume option is disabled. In this article, I'll introduce why Disk Management is unable to extend partition in Windows Server 2008 (R2) and how to fix this issue easily.

Why cannot extend volume in Windows Server 2008 R2 with Disk Management:

No adjacent Unallocated space

The size of a physical hard disk is fixed, a 500GB disk can't be decreased to 250GB or increased to 1TB. Therefore, before extending a hard drive partition, there must be "Unallocated" space.

Although Disk Management has "Shrink Volume" function to decrease partition, it can only make Unallocated space on the right when shrinking a partition. This space can't be extended to the right contiguous or any nonadjacent partitions with "Extend Volume" function.

As you see in my server, the 20GB Unallocated space is shrunk from D drive, Disk Management cannot extend volume C: and E: with this space.

If you want to extend partition C with Server 2008 Disk Management, you must delete the adjacent D: drive. If there is no right adjacent partition or you cannot deleted it, Disk Management is completely useless.

Extend greyed

File system is not supported

Extend is grayed

From Microsoft explanation, "Extend Volume" can only expand the partitions that are formatted with NTFS or without file system (RAW).

To show you this restriction, I converted D: drive from NTFS to FAT32. As you see, both Shrink and Extend Volume are grayed out, although there is adjacent Unallocated space on the right.

Different partition type

Because some people cannot extend C drive after shrinking D or other partition, some people ask if it is possible to enable Extend Volume by deleting D drive. It works on GPT disk, but on MBR disk, it depends.

For example, if both C and D drive are Primary partition, it works by deleting D. But if drive D is a Logical drive, Extend Volume is still disabled for C drive after deleting.

In Windows Disk Management, Unallocated space that deleted from Primary partition can't be extended to any Logical drive. Free space that deleted from Logical drive can't be extended to any Primary partition.

"Free" space is still part of the Extended partition, to convert it to Unallocated, you must delete all other Logical drives and the whole Extended partition.

Extend volume disabled

2TB restriction on MBR disk

If your hard disk is 2TB+, check it is MBR or GPT. You can only use 2TB space on a MBR disk. That means, Windows Server 2008 cannot extend partition past 2TB on MBR disk even if there's contiguou Unallocated space on the right. 

Why cannot extend partition in Windows Server 2008 with diskpart command

Diskpart has no graphic dialog box, it works via command prompt. In diskpart command window, input help extend, then you'll see the introduction and restrictions.

  1. The partition that you want to extend must be formatted with NTFS or without file system (RAW).
  2. The free (Unallocated) space must be adjacent and on the right side of the partition that you want to expand.
  3. Free (Unallocated) space and the partition must be on the same disk.

Better than Disk Management, diskpart can extend C drive by deleting D even if D is Logical drive.

Extend command limitation

What to do when Windows native is unable to extend volume in Server 2008 R2

In most cases, is the reason why you cannot extend partition in Windows 2008 server with diskpart command or Disk Management. To solve this problem, you need to run NIUBI Partition Editor and move Unallocated space next to C drive.

Download NIUBI Partition Editor and you'll see the main window with disk partition structure and other information.

NIUBI Partition Editor

Steps when you cannot extend volume in Windows Server 2008 R2:

Step 1: Right click the right adjacent partition (D:) and select "Resize/Move Volume", drag the  middle of this partition towards right in the pop-up window.

Move drive D

Then Unallocated space is moved to the left.

Move Unallocated space

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

Extend C drive

Then Unallocated space is combined to C: drive.

Move Unallocated space

Step 3: Click Apply on top left to execute.

If you have not shrunk a partition to get Unallocated space, shrink with NIUBI Partition Editor. It is able to make Unallocated space on the left while shrinking partition. To this tool, there's no difference to shrink and extend NTFS or FAT32 partition, Primary or Logical partition. You just need to drag and drop on the disk map, follow the steps in the video:

Video guide

If you use 2TB+ MBR disk, follow the steps to convert MBR to GPT.

Better than other tools, NIUBI Partition Editor has unique 1 Second Rollback, Virtual Mode, Cancel-at-will technologies and advanced file-moving algorithm to help repartition hard drive safely and much faster. It also helps you do many other disk partition management operations.