How to Shrink Partition/Volume in Windows Server 2016

by Allen, Updated on: October 2, 2021

Sometimes you need to shrink an allocated partition, for example, a partition is created too large, to optimize space usage, you need to shrink it and create more volumes. Another typical example is that C drive runs out of space, so you need to shrink other volume to get Unallocated space and then add into C drive. To shrink volume in Windows 2016 server without losing data, there are 2 kinds of tools: native Disk Management and 3rd-party disk partition software. In this article, I'll introduce how to shrink partition with Windows Server 2016 Disk Management tool, disadvantages of this native and the better way to shrink Server 2016 partition.

Shrink volume in Windows Server 2016 without software

From Windows Server 2008, Microsoft added Shrink Volume function in built-in Disk Management tool, which is able to decrease partition and make Unallocated space without losing data and on the fly. However, only NTFS partition is supported. Windows Server 2016 inherits the same function without any improvement, so you can't shrink partition for Windows 2016 server in some cases.

How to shrink volume in Windows Server 2016 Disk Management:

  1. Press Windows + X together on the keyboard and click Disk Management from the list.
  2. Right click the partition that you want to decrease and select Shrink Volume.
  3. Enter the amount of space to shrink in MB, and then click Shrink to execute. If you don't enter an amount manually, the maximum available free space will be used.
    Shrink partition

In a while, D drive in my server is shrunk from 50GB to 30GB, 20GB free space is converted to Unallocated on the right side.

Volume shrank

Disk Management only give you an option to enter an amount, you cannot decide the position to make Unallocated space on left or right side. It causes a serious issue that this Unallocated space cannot be extended to other partition. Because Disk Management Extend Volume function can only extend Unallocated space to the left contiguous partition.

The cases that unable to shrink volume in Server 2016 DM

Many server administrators encountered the issue that they cannot shrink partition with Server 2016 Disk Management, because Shrink Volume is disabled.

Reason 1: Only NTFS partition is supported

As I said above, Disk Management can only shrink NTFS partition. Another common FAT32 partition and any other types of partitions cannot be shrunk. To show you the truth, I formatted D: drive from NTFS to FAT32 in my test server. As you see, Shrink Volume is greyed out for this partition.

Shrink Volume disabled

Reason 2: File System error

Sometimes, when there's File System error in a partition, Disk Management won't allow shrinking it. As you see in the screenshot, there's 7.53GB free space in system C drive, but in the shrinking window, available free space is shown as 0.

Cannot shrink

Reason 3: There are unmovable files

In this situation, Shrink Volume function still works but it gives little available space to shrink, although there's large amount of free space. Have you noticed the tip in the shrinking volume window - "You cannot shrink a volume beyond the point where any unmovable files are located"?

Shrink limitation

For example: C drive has 4 blocks. If the unmovable files are located in block 3, you cannot shrink C drive to block 2 or 1 although they are blank.

Unmovable files

Comparing with data volumes, you are very likely encounter this issue while shrinking system partition C, because the unmovable files include Page File, Hibernation and other large system files, which are all located in C: drive by default.

Better way to shrink partition in Windows 2016 server

To shrink partition in Windows Server 2016, NIUBI Partition Editor is much easier and more powerful. Comparing with Windows native Disk Management, NIUBI has many advantages such as:

How to shrink partition in Windows Server 2016 without losing data:

  1. Download NIUBI Partition Editor, right click the partition that you want to shrink and then select "Resize/Move Volume".
  2. Drag either border towards the other side in the pop-up window, then this partition will be shrunk. (Note: if you want to expand C drive, shrink D drive and make Unallocated space on the left.)
  3. Click Apply on top left to confirm and execute. (All operations before clicking Apply only works in virtual mode.)

Watch the video how to shrink Server 2016 partitions:

Video guide

In Summary

Because of the inherent limitations, Windows Disk Management can only help you shrink NTFS partition to create new, or extend a NTFS partition by deleting the right contiguous partition. To shrink volume in Windows Server 2016, NIUBI Partition Editor is better choice. Comparing with other software, NIUBI is much safer and faster because of its unique 1 Second Rollback, Virtual Mode, Cancel-at-well technologies and advanced file-moving algorithm. It also helps you move, merge, copy, convert, hide, wipe partition and much more.