Windows Server 2016 Extend Volume option is greyed out

Microsoft added “Extend Volume” and “Shrink Volume” functions in Disk Management from Windows Server 2008. It is very easy to understand, Extend Volume is used to increase partition size and Shrink Volume is used to reduce partition size. When system partition C is getting full, many server administrators try to shrink D and expand C drive. However, they find that Server 2016 Extend Volume option is grayed out, even after shrinking any other partitions. In this article, I’ll introduce the reasons why Extend Volume greyed out in Windows Server 2016 Disk Management and what to do when Extend Volume is disabled to C drive.

Extend volume grayed

The cases Extend Volume greyed out in Server 2016 DM

First of all, let’s see the common scenarios of Extend Volume option greyed out in Windows 2016 Disk Management.

Scenario 1

If you right click a drive without any Unallocated space, Extend Volume is absolutely grayed out.

Cannot extend C

Scenario 2

Some people try to shrink D to get Unallocated space via “Shrink Volume” function.

Shrink drive D

Some free space is taken out from D but Extend Volume is disabled to C drive, too.

Extend volume disabled

Scenario 3

Some people even tried to delete the contiguous D: drive.

All operations below are just used to explain why Extend Volume grayed out in Windows 2016 server. They are not the steps to help fix this issue.


Delete drive D

However, Extend Volume is still greyed out after deleting.

Cannot extend C

Scenario 4

Some people find that the space deleting from D shows as “Free” instead of “Unallocated”. This is because that D: drive is a Logical drive. Different with independent Primary partition, Logical drive belongs to the Extended partition. If you want to convert Free space to Unallocated, you must delete all Logical drives and then the entire Extended partition.

Delete volume E

Delete the Extended partition.

Delete extended partition

Now, the disk space shows as Unallocated, and Extend Volume is enabled to C drive.

Extend available

Reasons why Extend Volume greyed out in Windows Server 2016 Disk Management:

  1. You may try to extend a FAT32 partition. From Microsoft explanation, only NTFS and RAW format partition can be extended.
  2. Extend Volume only works when there’s contiguous Unallocated space on the right side, but Disk Management cannot make such required space via Shrink Volume function.
  3. If the adjacent drive D is a Logical partition, you cannot extend C drive by simply deleting D. You must delete all Logical drives and the Extended partition.
  4. If you try to extend partition in a 2TB+ MBR disk, you may encounter the same issue, because the maximum partition size is 2TB on MBR disk.

What to do when Extend Volume greyed out in Server 2016

Open Disk Management in your own server, check your disk partition structure and other information. Find out the reason and follow the corresponding method below.

Let’s begin from the most common situation, Extend Volume greyed out to C drive after shrinking D (or other partition).

Volume shrank

How to fix Windows Server 2016 Extend Volume greyed out in C drive:

Step 1: Download and install NIUBI Partition Editor. You’ll see the same disk partition structure in the main window. There’s 10GB free space that is shrunk from D.

Unallocated behind D

Step 2: Right click D: drive and select “Resize/Move Volume“.

Move volume

In the pop-up window, drag the middle block towards right.

Drag to move

Move D drive

Move D

Click OK and back to the main window, the 10GB Unallocated space is moved to the left, now it is behind C: drive.

Unallocated moved

Step 3: Right click C: drive and select “Resize/Move Volume” again. In the pop-up window, drag right border rightwards to merge this Unallocated space.

Drag to extend

Extend C drive

Extend volume

Click OK and back to the main window, the Unallocated space that shrank from D is added to C drive.

Volume extended

Step 4: Click Apply on top left to execute, done. Check in Disk Management, yes it works.

Note: real disk partitions won’t be changed until click Apply to confirm.

C drive extended

Follow the full solution here.

In Summary

No adjacent Unallocated space is the most common reason why Extend Volume greyed out in Windows Server 2016. To solve this problem, you just need to move Unallocated space behind C drive. There are other reasons why Extend Volume option is disabled in Server 2016. No matter for which reason, this issue can be fixed easily with NIUBI Partition Editor, check the video:


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