Can't extend volume

Cannot extend volume in Windows Server 2012

This article introduces why can’t extend volume in Windows Server 2012 (R2) Disk Management and what to do if cannot extend disk partition with it.

About Server 2012 Extend Volume feature

The same with other Windows versions, low disk space is the most common issue in Server 2012 (R2). Comparing with other data volumes, the system C drive is very likely getting full. Of course you can back up everything, delete and recreate partition, finally restore and verify. The server OEM manufacturers will give you such solution if you contact them. If you do like this, the whole weekend may be wasted. Furthermore, server is offline during the whole process.

Obviously, it can’t be better if you can resize disk partitions without recreating volume and restoring. To help repartition hard drive, Microsoft provides Shrink Volume and Extend Volume in Disk Management of Windows 7 and subsequent versions. However, many people feedback that they can’t extend volume in Windows Server 2012 Disk Management. The typical example is that Extend Volume greyed out for C drive after shrinking D.

Of course you can still shrink and extend partition via DiskPart command prompt, but in fact, Shrink and Extend Volume functionalities are GUI version of shrink and extend command of DiskPart. That means, if the server disk partition layout and geometry does not meet the requirements, you cannot extend partition for Server 2012 with both GUI DM and DiskPart command.

Before finding a solution, you should know the reason why Extend Volume doesn’t work.

Why can’t extend volume in Server 2012 DM

There are 4 command reasons and I’ll introduce one by one.

Reason 1 No Unallocated space

A 256GB hard disk can’t be increased to 512GB, so before extending a volume, you must delete or shrink another one to get Unallocated space.

Reason 2 Unallocated space isn’t right adjacent

Extend Volume functionality can only expand the volume with adjacent Unallocated space, in addition, Unallocated must be on the right side. This is serious restriction, right? In fact, Shrink Volume also has limitation: it can only shrink a volume to left and produce Unallocated space on the right side.

To show you these limitations, I shrank drive D and got 20GB Unallocated space. As you see, I can’t extend volume C and E, because Unallocated space is non-adjacent to C and on the left side of E.

Can't extend volume

 Only NTFS partition is supported

Another common FAT32 and any other types of partitions are not supported. That means, even if there is right adjacent Unallocated space, Extend Volume is still disabled.

To show you this restriction, I converted drive D to FAT32. As you see, both Shrink and Extend Volume option are grayed out.

 Disk space can’t be transferred between Primary and Logical partition

Unallocated space deleted from a Primary partition cannot be extended to any Logical partition. Free space deleted from Logical partition can’t be extended to any Primary partition.

To show you this restriction, I create a Logical partition with the 20GB Unallocated space and then deleted it.

As you see:

What to do when cannot extend partition

No matter which reason that cause you can’t extend volume in Windows Server 2012 (R2), it is very easy to solve these problem. You just need to download NIUBI Partition Editor to drag and drop on the disk map.

The rule: drag either border towards other side to combine contiguous Unallocated space, when Unallocated is nonadjacent, move and then combine.

For example: how to extend volume C and E after shrinking D:

Download NIUBI Partition Editor, right click drive D and select “Resize/Move Volume”.

Partition Editor

Drag the middle position rightwards in the pop-up window.

Move partition D

Unallocated space is moved to the left side.

Drive D moved

Right click C drive and select “Resize/Move Volume” again, drag right border rightwards in the pop-up window.

Extend C drive

Unallocated space is combined into C drive.

C drive extended

If you want to extend drive E with the 20GB Unallocated space, it’s easier. Simply right click drive E and select “Resize/Move Volume”, drag left border leftwards in the pop-up window.

Extend drive E

Unallocated space is combine to drive E.

Drive E extended

Watch the video how to shrink and extend volume on Windows Server 2012 (R2):

There are several reasons that cause you can’t extend volume with Server 2012 Disk Management. In these cases, download NIUBI Partition Editor and follow the steps above and this issue can be solved easily. Besides shrinking and extending volume, it helps do many other operations.


Reason/Solution – cannot extend volume on Windows Server 2012.
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