Cannot extend volume in Windows Server 2016

Updated on: November 16, 2019

This article explains why you can't extend volume in Windows Server 2016 Disk Management and the corresponding solution when you are unable to extend partition for Server 2016.

Hard disk drives are allocated while installing Operating System, but you need to reallocate the partitions after running the server for a period of time. The typical example is that C drive is getting full.

To help solve this problem, Microsoft provides Extend Volume function in Disk Management from Server 2008. Windows Server 2016 inherited the same function without any improvement. Many server administrators feedback that they cannot extend volume with Server 2016 Disk Management, because Extend Volume is greyed out. This article explains all probable reasons why you are unable to extend volume in Windows Server 2016 Disk Management and the corresponding solutions.

Why can't extend volume in Server 2016 after shrinking

A 500GB disk can't be increased to 1TB (except virtual disk), so before extending a partition, you must delete or shrink other one to get Unallocated space. Disk Management has Shrink Volume function that is able to decrease partition size to make Unallocated space without losing data, so many people did this, but Extend Volume is disabled for C drive after shrinking D.

Cannot extend volume

This is because:

  • Extend Volume function can only add Unallocated space to the left contiguous partition.
  • Shrink Volume can only make Unallocated space on the right.

As you see, the 20GB Unallocated space is non-adjacent to C drive and is on the left of E, so Extend Volume is greyed out.

This is the most common reason why you can't extend volume in Server 2016 Disk Management. To solve this problem, if you want to extend system C drive, you need to move Unallocated space behind C drive with NIUBI Partition Editor Server.

Solution:

When you cannot extend partition in Windows Server 2016 Disk Management because the Unallocated space is nonadjacent to C drive after shrinking D, follow the steps below:

  1. Download NIUBI Partition Editor, right click drive D and select "Resize/Move Volume", drag the middle towards right in the pop-up window.
  2. Right click C: drive and select "Resize/Move Volume" again, drag right border towards right to combine Unallocated space.
  3. Click Apply on top left to execute.

NIUBI Partition Editor is designed to work in virtual mode, real disk partition won't be modified until you click Apply to confirm. If you did something wrong, simply click "Undo" to cancel. The pending operations marked as Check can be done without rebooting server.

Watch the video how to operate:

Video guide

Why cannot extend partition after deleting

Because Disk Management is unable to extend partition C after shrinking D, some people tried to delete D instead, but Extend Volume is still disabled. There are 2 common reasons why you cannot extend partition in Server 2016 Disk Management after deleting the right contiguous volume.

Extend Volume function only support extending NTFS and RAW (no file system) partition, so another common FAT32 and any other types of partition can't be extended even if there is adjacent Unallocated space on the right side.

Extend Volume disabled

The type of the partitions that you want to delete and extend are different. In MBR style hard disk, Free space deleted from a Logical partition can't be extended to any Primary partition. Unallocated space deleted from Primary partition can't be extended to any Logical drives.

Extend Volume greyed out

Solution:

When you cannot extend volume in Windows Server 2016 because of non-supported FAT32 partition or the restriction between Primary and Logical partition, simply combine Unallocated space with NIUBI Partition Editor. Watch the video how to do this:

Video guide

Why unable to extend volume on 2TB+ MBR disk

Extend Volume grayed

To a server, it is very common to use 2TB to 4TB single disk or over 10TB RAID array. If you initialized the disk as MBR, you'll find that only 2TB disk space can be used, the rest disk space is shown as Unallocated.

As the screen shot shows, drive H is NTFS and there is right contiguous Unallocated space, but Disk Management still cannot extend this partition.

Solution:

To solve this problem, you need to you convert disk from MBR to GPT and then extend partition(s) with Unallocated space on the end of this disk. Watch the video how to do this:

Video guide

If you have not shrunk any partitions, follow the steps in the video, then you can expand other volume much more easily.

In Summary

When you cannot extend partition in Windows Server 2016 Disk Management, find out the reason according to your own disk partition structure, then follow the corresponding solution. Besides shrinking, moving and extending partitions, NIUBI Partition Editor helps you merge, copy, convert, defrag, wipe, hide partition, scan bad sectors and much more. It is much faster and safer than other tools because of its unique protection technologies and file-moving algorithm.

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