Windows Server 2019 Cannot/Unable to Extend Volume

by Jordan, Updated on: March 26, 2020

This article introduces why cannot extend volume in Windows Server 2019 and what to do if unable to extend partition in Server 2019 Disk Management.

The same with previous versions, Windows Server 2019 has native Disk Management to create, delete and format partition. It also has the ability to decrease and increase partition size on the fly with built-in Shrink and Extend Volume functions. However, many people feedback that Windows don't allow to select Extend Volume, or can't extend volume C after shrinking D. In this article, I'll explain all possible reasons why cannot extend volume in Windows Server 2019 Disk Management, and what to do when this native tool is unable to extend disk partition.

Why can't extend volume in Server 2019 Disk Management

There are 4 common reasons why you cannot extend partition in Windows Server 2019 Disk Management, I'll introduce one by one.

1. No adjacent Unallocated space on the right

The size of a physical hard disk is fixed, so before extending a partition, you must delete or shrink another one to get Unallocated space. You won't lose data by shrinking a partition in Server 2019 Disk Management (in most cases), so it is much better than deleting. The problem is, you still cannot extend partition after shrinking any other one via Disk Management. As you see in the screenshot, I cannot extend C drive and E after shrinking D in my test server.

Extend Volume disabled

This is because:

Disk Management can only make Unallocated space on the right while shrinking a partition, but Extend Volume function can only add Unallocated space to the left contiguous partition.

Unallocated space shrunk from D drive is nonadjacent to C drive and is on the left of E drive, this is the reason why Extend Volume doesn't work.

2. File System is not supported

Extend Volume can only extend the partitions that are formatted with NTFS file system or without file system (RAW). FAT32 and any other types of partitions can't be extended. As you see in the screenshot, I cannot extend volume D, although there's contiguous Unallocated space on the right, because it is a FAT32 partition.

3. Different partition type

Because Disk Management cannot extend C drive by shrinking D, some people try to delete D. If D is a Primary partition, Extend Volume will be enabled for C drive after deleting D.

As the screenshot shows, if D is a Logical partition, you still cannot extend volume C after deleting D.

In MBR disk, Unallocated space deleted from a Primary partition can't be extended to any Logical drives, Free space deleted from a Logical drive can't be extended to any Primary partitions.

Extend Volume disabled

4. 2TB limit in MBR disk

Another limitation to MBR disk is that the maximum disk/partition size is 2TB. If you initialize a 4TB hard disk as MBR, you can only use 2TB space, the remaining space will be shown as Unallocated. When you right click this space, all options are greyed out.

As you see in the screenshot, I cannot extend drive F although there's contiguous Unallocated space on its right side.

Extend Volume greyed out

What to do if unable to extend partition in Windows Server 2019

Open your server Disk Management and find out the reason why Extend Volume greyed out, then follow the corresponding solution below according to your own disk partition configuration.

1: Move and merge Unallocated space

If you already shrunk D and got Unallocated space via Disk Management, move Unallocated space to the left and then combine to C drive with NIUBI Partition Editor.

If you want to expand another data volume E, you can combine Unallocated space directly without moving. To do this, right click it in NIUBI and select "Resize/Move Volume", drag left border towards left in the pop-up window.

Download NIUBI Partition Editor and follow the steps in the video:

Video Server 2019

2: Shrink and extend partition with NIUBI

If you want to extend a FAT32 partition or the type of partitions that you want to delete/shrink and extend are different, resize with NIUBI Partition Editor. There's no difference while resizing NTFS and FAT32 partition, or resizing Primary and Logical partition. Follow the steps in the video:

Video Server 2019

3: Convert MBR disk to GPT first

If you want to extend a partition beyond the limit of 2TB, follow the steps in the video to convert MBR disk to GPT and then combine Unallocated space to other partition(s):

Video Server 2019

Take care of system and data while extending disk partition

There's potential system damage and data loss risk while shrinking and moving partitions, so you'd better make a backup first and run safe partition software. Better than other tools, NIUBI Partition Editor is much safer and faster because of the advanced technologies:

As a disk partition management toolkit, it helps you do many other operations.

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