How to Resize Partition in Windows Server 2012 R2

by Andy, Updated on: July 5, 2022

Disk partitions are allocated by server manufacturer or by yourself when installing operating system. After running the server for a period of time, you need to adjust partition size. The typical example is that system partition C is getting full. Other partitions for exchange, database and backup may be running out of space, too. To solve this problem, nobody likes to waste a long time to recreate partitions, restore everything and verify data. Therefore, many server administrators ask if it's possible to resize Server 2012 partition without losing data. The answer is yes, but you'd better use safe disk partition tool. Unreliable software is very likely cause system damage and data loss. In this article I'll introduce how to resize partition in Windows Server 2012 (R2) safely and easily.

1. Which tool to resize Server 2012 partition

There are two kinds of tools to help resize disk partition in Windows 2012 server: Windows built-in Disk Management and 3rd-party partition software.

Advantage of Windows Disk Management:

Disadvantages to resize partition with Server 2012 Disk Management:

  1. Only NTFS partitions can be shrunk and extended.
  2. Unallocated space can only be made on the right while shrinking a partition.
  3. Sometimes you cannot shrink partition such as when there are "unmovable" files.
  4. Only the partition with adjacent Unallocated space on the right can be extended, Extend Volume is disabled for all other partitions.
  5. Operations can't be undone, disk partitions will be modified instantly even if you did something wrong.
  6. Lack of data protection and other advanced disk partition management ability.

How to run Disk Management to resize partition in Windows Server 2012 R2:

  1. Right click a NTFS partition and select "Shrink Volume", click Shrink button to decrease with default maximum available space, or enter an amount by yourself and click Shrink.
  2. Before extending a partition, you must delete the contiguous volume on the right side. After that, right click this NTFS partition and select "Extend Volume", then simply click Next in pop-up "Extend Volume Wizard".

The partitions to be deleted and extended must be the same Primary or Logical partition.

If you just want to decrease a NTFS partition to create new volume, you may try Windows Disk Management. If you want to extend a partition by shrinking another one, Disk Management cannot help you. Because it cannot make required Unallocated space to enable Extend Volume function.

Extend volume disabled

As you see in the screenshot, Disk Management can only extend partition when there's adjacent Unallocated space on the right. After shrinking D drive, Unallocated space is on the left of E drive and is nonadjacent to C drive. This is the reason why many people feedback that Extend Volume greyed out in Server 2012.

Better than Disk Management, NIUBI Partition Editor can make Unallocated space on either left or right when shrinking a partition. It can extend a partition with either contiguous Unallocated space. If there's nonadjacent Unallocated space, it is able to move partition and make Unallocated space to be contiguous.

Why there's risk when resizing disk partition

To resize partition in Windows Server 2012 (R2), for example shrinking D to extend C drive:

  1. The start and end position as well as other parameters of drive C and D must be modified correctly.
  2. All files in drive D will be moved to new locations, all parameters of these files will be changed, too.
  3. System boot related files must be updated.

Any slight error could cause system/data damage. Many people feedback issue that caused by unreliable partitioning software, for example: system boot failure with error message or black screen. Partition changed to be RAW and Windows ask to reformat it.

Better than other tools, NIUBI Partition Editor has innovative technologies to your protect system and data.

Because it does't require rebooting to clone disk partition with NIUBI, you can clone system disk regularly as backup. Whenever the system disk is done, it just requires several minutes to restart server and boot from the clone disk. Because of the advanced  file-moving algorithm, this program is 30% to 300% faster. All these abilities are useful and important when you change partition size in Windows Server 2012 and other versions.

2. How to resize partition in Windows Server 2012 R2 safely

It is very easy to resize Server 2012 volume with NIUBI Partition Editor, you just need to drag and drop on the disk map.

Download the server edition, right click a partition such as D: 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)

Shrink D

Then drive D is resized and some Unallocated space is made on the left.

Drive D shrank

If you drag right border towards left, Unallocated space will be made on the right of D drive.

Right click C: drive and select "Resize/Move Volume" again, drag right border towards right in the pop-up window.

Extend C drive

Then this Unallocated space will be extended to C drive.

C drive extended

If you want to extend E: drive, shrink D and make Unallocated space on the right. Then drag left border towards left when running "Resize/Move Volume" for E drive.

To avoid wrong operation, NIUBI Partition Editor is designed to work in virtual mode. To change real disk partitions, remember to click Apply to take effect.

3. Video guide to resize Server 2012 partition

As long as there's free space on the same disk, you can transfer and add to the partition that you want to expand. Watch the video how to resize partition in Server 2012 R2:

How to extend C drive by resizing other data volumes:

Video guide

How to extend D drive by resizing C or other volumes:

Video guide

In some servers, C drive is getting full but there is no other partition, or no available free space on the same disk. In that case, no software can add space to C drive from another separate disk. To increase C drive or other partition, you can copy disk to a larger one and extend partition with extra disk space. Follow the steps in the video:

Video guide

If you want to resize RAID partition or resize virtual partition in VMware/Hyper-V VM, there is no difference. Do not break array or do any operations to RAID controller, just follow the steps above.

Besides resizing partition in Windows Server 2012/2016/2019/2022/2003/2008, NIUBI Partition Editor helps you do many other disk partition management operations.