Resize/Extend C Partition in Hyper-V Windows Server 2016

by John, Updated on: July 28, 2022

Hyper-V is common used virtual machine tool and many Windows server are running from it. The same with physical server, C: drive in virtual machine is getting full. Many people ask whether there's any difference when resizing virtual partition in Hyper-V, and whether it's safe to extend system C drive in Hyper-V running Windows Server 2016/2019/2022. This article introduces how to resize and extend Hyper-V partition in Server 2016 with both Windows native and 3rd-party tools.

How to resize partition in Hyper-V without any software

Open Windows Server 2016 in Hyper-V, press Windows and X together on the keyboard, and then click Disk Management in the list.

Right click a partition, you'll see some options. Among them, "Shrink Volume" and "Extend Volume" is used to adjust partition size without losing data (in most cases). Both functions only support NTFS partition, FAT32 and any other types of partitions cannot be shrunk or extended.

Most of partitions in Windows 2016 server are formatted with NTFS file system by default, but Disk Management still cannot help you extend a partition by shrinking another one, because:

Unallocated space that shrunk from D drive is nonadjacent to C. Therefore, Disk Management cannot help you extend C drive in Hyper-V by shrinking other volume. Only when you want to shrink a NTFS to create new volume, or extend a NTFS partition by deleting the right contiguous volume, you can resize partition without any software.

If you want to extend partition C in Hyper-V by shrinking another one without losing data, only 3rd-party software can help you. However, you'd better back up in advance and run safe partition software. Otherwise, there's potential system and partition damage risk. Better than other tools, NIUBI Partition Editor has innovative technologies to protect system and data such as:

How to extend C drive in Hyper-V Windows Server 2016

To extend C drive in Hyper-V running Windows Server 2016, firstly, check there's free space in D other partition on the same virtual disk. If yes, it is very easy. Shrink this partition with NIUBI Partition Editor, then part of free space will be converted to Unallocated, and then add this Unallocated space to C drive. After resizing partitions, Operating System, programs, Windows services and everything else keep the same with before, except partition size.

Steps to extend C partition in Hyper-V Windows Server 2016/2019/2022:

  1. Download NIUBI Partition Editor and install to Hyper-V virtual server.
  2. Right click the right contiguous partition D: (in some server is E:) and select "Resize/Move Volume". Drag left border towards right in the pop-up window, or enter an amount in the box of Unallocated space before.
  3. Right click system partition C: and select "Resize/Move Volume" again, drag right border towards right to combine Unallocated space in the pop-up window.
  4. Click Apply on top left to execute. (If you did something wrong, simply click Undo to cancel th pending operation.)

Video guide

If you want to get free space from any non-adjacent volume, there's an additional step to move Unallocated space next to C drive.

How to extend Hyper-V partition when virtual disk is full

In a physical server, if a system disk is full, you have to clone it to a larger one, and then extend system C drive with additional disk space. But in Hyper-V virtual server, it is much easier.

  1. Follow the steps to expand Hyper-V virtual disk. After that, additional space will be shown as Unallocated at the end of original virtual disk.
  2. Follow the steps to combine Unallocated space to the partition(s) that you want to extend.

Besides shrinking and extending partition in Hyper-V or physical Windows 2016 Server, NIUBI Partition Editor helps copy, convert, merge, defrag, hide, wipe partition, scan bad sector and much more.