Extend Volume greyed out in Windows Server 2016

The same with other version, Windows Server 2016 has native Disk Management tool. It has “Extend Volume” function to help increase partition size. When system partition C is getting full, many server administrators try to shrink D and expand C drive. However, they find that “Extend Volume” option is grayed out in windows Server 2016 Disk Management. In this article, I’ll introduce the reasons why Extend Volume greyed out in Server 2016 Disk Management and what to do when Extend Volume is disabled for C drive.

Extend volume grayed

The cases Extend Volume greyed out in Server 2016

To better explain why Extend Volume is disabled in Windows Server 2016 Disk Management tool, first of all, let’s see the common scenarios.

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

Free space is taken out from D but Extend Volume is still disabled for C drive.

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 for C drive after deleting D.

Cannot extend C

Scenario 4

Because D is a Logical drive, the space is shown as “Free” instead of “Unallocated”. 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 for C drive.

Extend available

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

  1. You may try to extend a FAT32 partition. From Microsoft explanation, only NTFS and RAW partition can be extended.
  2. Extend Volume only works when there’s contiguous Unallocated space on the right, 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. The maximum partition size is 2TB on MBR disk. Therefore, you can’t extend a partition to 2TB+, even if there’s adjacent Unallocated space on the right.

What to do when Extend Volume is grayed 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 C drive greyed out after shrinking D (or other partition).

Volume shrank

How to fix Windows Server 2016 Extend Volume greyed out for 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 of D drive 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 and 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, Unallocated space is added to C drive in “Virtual Mode”.

Volume extended

Step 4: Click Apply on top left to execute, done.

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

C drive extended

Watch the video how to operate:

Besides help fix Extend Volume greyed out in Windows Server 2016/2019/2022/2003/2008/2012, NIUBI Partition Editor helps you do many other disk partition management operations.

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