Windows Server 2012 extend disk partition

Updated on: November 16, 2019

This article introduces how to extend partition in Windows Server 2012 (R2) without data loss. 3 ways to extend disk partition with detailed steps.

Extend partition with Server 2012 Disk Management

When a partition is running low on disk space, you can extend it without wasting a long time to recreate partitions and restore from backup. Some people like to use Windows native tools thinking it has best compatibility. When extending partition in Windows Server 2012, there is indeed a Disk Management tool, which has Extend Volume function to increase size of a partition without losing data.

However, it only works under very restricted condition because of the limitation of both Shrink and Extend Volume.

Before extending a drive, you must delete or shrink other volume to get Unallocated space, and then combine Unallocated space to the partition that you want to extend.

In Server 2012 Disk Management:

  • Shrink Volume can only shrink a partition towards left and generate Unallocated space on its right side.
  • Extend Volume can only extend the partition with adjacent Unallocated space on its right side.

After shrinking a volume (such as D:), Extend Volume is disabled for all other partitions. The only way to extend partition with Server 2012 Disk Management is by deleting the adjacent partition.

Extend volume disabled

Extend partition C by shrinking D or E

When system partition C becomes full, you cannot solve this problem by simply transferring files. Comparing with data volumes, C drive is very likely running out of space. So in this article I'll introduce how to extend system partition C first, it is similar if you want to extend any data partition.

Obviously, it is a bad idea to delete drive D to get adjacent Unallocated space. Instead, you can shrink drive D and make Unallocated space on the left side. To accomplish this task, you just need to drag and drop on the disk map of NIUBI Partition Editor.

Download it and you'll see all disk partitions with structure and other information in the main window. Original C: drive is 40GB and D is 70GB.

NPE Server

Steps to extend partition C: in Windows Server 2012 with NIUBI:

Step 1: Right click drive D: and select "Resize/Move Volume", drag left border towards right in the pop-up window. (or enter an amount manually)

Shrink D

Then partition D is shrank and Unallocated space is made on its left side.

Drive D shrank

Step 2: Right click drive C: and select "Resize/Move Volume" again, drag right border towards right to combine Unallocated space.

Extend C drive

Then partition C is extended to 60GB.

C drive extended

Step 3: Click Apply on top left to execute, done.

NIUBI is designed to work in virtual mode, real disk partitions won't be changed until click Apply to confirm.

How to extend partition C with E:

If there is not plenty of unused space in the contiguous partition (D:), you can shrink the non-adjacent partitions (E:).

Right click E: and follow STEP 1 above to make Unallocated space on the left side. Before following STEP 2 to combine Unallocated space into C, there is an additional step to move Unallocated space from right of D to the left side.

To do this, right click D: and select "Resize/Move Volume", drag middle position towards right in the pop-up window:

Move drive D

Watch the video how to extend partition C in Windows Server 2012:

Video guide

Extend drive D by shrinking C or E

To extend any data volumes, it is similar, you can shrink either system C: drive or other data volume E. Follow the steps in the video to extend partition D in Windows Server 2012:

Video guide

Generally speaking, you can extend either system partition C or data volume D by following steps above. However, in some servers the disk partition configuration are special. For example: there is no other partition in the same disk, or not enough unused space in all other partitions. In that case, follow the method below.

Extend partition with other disk

1. If you want to extend partition C: but there is no other partition or not enough free space in the same disk.

In this case, you may clone entire disk to a larger one, and then extend partition C (and other ones) with extra disk space. (Copying single C drive cannot ensure Windows bootable.)

Video guide

It is suggested to select the option to turn off computer after clicking Apply.

After copy complete, replace the small disk or change BIOS to boot from large disk.

2. If you want to extend a data partition but cannot get enough free space from all other partitions in the same disk.

In this case, you may clone this partition to another disk.

Video guide

Unallocated space in the target disk should be larger than the used space of this partition.

If you installed programs or any Windows services in the partition (such as D:), remember to change drive letters one by one. To other data volumes, you may ignore this step.

In summary

To extend partition in Windows 2012 Server, the native Disk Management tool is useless. NIUBI Partition Editor provides many ways to help you. Select the corresponding method according to your disk partition structure.