Extend Volume/Partition on Windows Server 2012 R2

Updated on: November 16, 2019

This article introduces how to extend volume on Windows Server 2012 R2 without losing data, detailed steps to enlarge/extend Server 2012 partition with native and 3rd-party tools.

Many server administrators need to repartition hard drive and extend system partition after running the server for a period of time, but it is not an easy task if you have no such experience before. Because there's potential system and partition damage risk, you'd better back up first and run safe server partitioning tool. Windows Server 2012 has its native tool, but because of many limitations it is not the best choice.

About Server 2012 Extend Volume function

The same with previous version, Windows Server 2012 provides built-in Extend Volume function in Disk Management tool, which can be used to expand both system partition and data volumes without losing data. In fact, Extend Volume is the GUI version of "Extend" command in DiskPart. Both native tools have serious restrictions that cause you unable to extend volume on Server 2012.

Extend Volume restrictions:

Another Shrink Volume function only support NTFS partition, too. The worst, it can only shrink a volume towards left and generate Unallocated space on the right side. This space cannot be extended to any other volume. In other words, if you want to extend a volume by shrinking other one in Server 2012 Disk Management, it is impossible.

As you see, after shrinking drive D the 20GB Unallocated space is nonadjacent to C and on the left side of E, so Extend Volume is grayed out for both partitions.

Extend volume disabled

How to extend partition in Windows Server 2012 DM

From the screenshot above, the 20GB Unallocated space can only be extended to left contiguous drive D. If you want to extend C drive with Disk Management, the only option is by deleting drive D to get right adjacent Unallocated space. (Disk Management cannot expand the last partition E)

  • Do not delete drive D if you installed programs or any Windows services in it, otherwise, the programs and services will stop working.
  • Remember to back up or transfer files before deleting a volume.
  • The partitions that you want to delete and extend must be the same Primary or Logical partition.

Steps to extend volume with Windows Server 2012 Disk Management:

  1. Press Windows logo and R together on your keyboard, type diskmgmt.msc and press Enter to open Disk Management.
  2. Right click the right contiguous partition and select Delete Volume.
  3. Right click the NTFS partition that you want to expand and select Extend Volume.
  4. Simply click Next till Finish in the pop-up Extend Volume Wizard windows.

Extend Volume Wizard

If you cannot or do not want to delete partition, server partition software is needed to extend volume on Windows Sever 2012.

How to extend server volume with partition editor

Comparing with Windows Disk Management, NIUBI Partition Editor has many advantages such as:

There are many server partitioning software and they are much more powerful than Disk Management, but not all are safe enough to shrink and extend disk partition. If any software caused a disaster, it costs a long time to restore everything.

NIUBI has 3 technologies to protect system and data:

  1. Virtual mode - avoid incorrect operations by listing all as pending, real disk partitions won't be changed until click Apply to confirm.
  2. Cancel-at-well - if you applied any incorrect operations, you can cancel the ongoing operations without losing data.
  3. 1 Second Rollback - if anything goes wrong while resizing and extending partition, it automatically reverts server to original status in a flash.

It is also 30% to 300% faster because of its advanced file-moving algorithm.

Download NIUBI Partition Editor, you'll see all disks with partition structure on the right, available operations to selected disk or partition are listed on the left side and by right clicking.

NIUBI Partition Editor

Detailed steps to extend volume on Windows Server 2012 R2:

Step 1: right click drive D: and select "Resize/Move Volume" to shrink it.

If you drag left border towards right, or enter an amount in the box of Unallocated space before:

Shrink D rightwards

Then Unallocated space is generated on the left side of D.

Unallocated produced

If you drag right border towards left, or enter an amount in the box of Unallocated space after:

Shrink D leftwards

Then Unallocated space is generated on the right side of D.

Unallocated generated

Step 2: right click drive C: or E: and run "Resize/Move Volume" again to expand it.

To extend system drive C, drag right border towards right in the pop-up window.

Drag to extend

Then Unallocated space is extended into C: drive.

C drive extended

To extend data drive E, drag left border towards left in the pop-up window.

Drag to extend

Then Unallocated space is extended into E: drive.

Drive E extended

Step 3: Click Apply on top left to confirm and execute.

If you want to extend volume C by shrinking the non adjacent E, there's an additional step to move partition D.

Watch the video how to extend partition in Windows Server 2012 R2 by shrinking other volume:

Video guide

About extending RAID 0/1/5 partition (RAID array)

It is very common to use hardware RAID arrays for a server, some server use RAID 1 for Operating System, RAID 5 for data storage, some server us RAID 5 for both OS and data.

When shrinking and extending RAID partition in Windows Server 2012, do not break array no matter you use RAID 0, 1, 5, 10 or any other types. Do not do any operations to any brand of RAID controller, just follow the steps above.

If there's no available free space in a physical or RAID virtual disk, no software can extend a partition by adding free space from another separated disk. In that case, follow the step to clone disk to a larger one and extend partition(s) with additional disk space.

How to extend virtual partition for VMware/Hyper-V

If you run Windows Server 2012 as guest virtual machine in VMware or Hyper-V, there's also no difference to extend volume if you can shrink any other one on the same virtual disk.

If there's no available free space, you can increase disk size without copying to other one, follow the guide below:

After expanding disk, additional disk space will be shown as Unallocated on the end of original disk. Follow the method in the video and combine Unallocated space to other partition(s).

In Summary

Because of the inherent limitations, the built-in Disk Management (and Diskpart command) can only help you extend NTFS partition by deleting the right contiguous one. To extend volume on Windows Server 2012 (R2), 3rd party software is better choice. However, you'd better back up first and use reliable tool. As the safest disk partition software, NIUBI Partition Editor helps you shrink, extend and move partitions easily and safely. It also helps you do many other operations.